I have an old Acer Aspire X3990, used almost daily for 10+ years;
greatly modified to be a really good work-horse.
Suddenly I switch it on and instead of booting it whistles from the PSU.
I need a new PSU, but they're hard to find for such a heirloom.
Here's a picture of the PSU;
https://ibb.co/0hvpJkz
And here's a possible replacement;
https://tinyurl.com/2zrcs8j2

I should think that PSU technology has advanced quite a bit.
I might be able to find something better.

Any suggestions from the workbench?

Ed

On 5/30/2023 7:03 AM, Ed Cryer wrote:
> I have an old Acer Aspire X3990, used almost daily for 10+ years; greatly modified to be a really good work-horse.
> Suddenly I switch it on and instead of booting it whistles from the PSU.
> I need a new PSU, but they're hard to find for such a heirloom.
> Here's a picture of the PSU;
> https://ibb.co/0hvpJkz
> And here's a possible replacement;
> https://tinyurl.com/2zrcs8j2
>
> I should think that PSU technology has advanced quite a bit.
> I might be able to find something better.
>
> Any suggestions from the workbench?
>
> Ed

Maybe that's a FlexATX ?

They come up to 90% efficient and 600W.
The previous generation would be somewhat less on both numbers. 80% 230W.

You check the label with the output amperage listed, and
then compare the replacement numbers to the original.

For example, if the original was 12V @ 13A and the
replacement is 12V @ 50A, it means both of them could
manage to power a 13A load, and both would be suitable.

if the replacement supply only made 12V @ 6A, it would
presumably be too weak as a replacement.

On modern computers, there isn't much that runs off -12V.
That's why the current there is 0.3 amps. The RS232 serial
port runs off that voltage.

The -5V output was discontinued more than 20 years ago.

The +3.3V, +5V, +12V are the mainstream outputs.

The +5VSB is the "supervisor voltage" and powers the
machine while it sleeps, and powers the machine enough
so it can feel when the front button was pressed (soft ON/OFF).
If the +5VSB has 3 amperes on offer, that's pretty generous.
It does not offer a lot of amperes for charging an iPad via
a USB connector, but it's otherwise a start at a power source.

The FlexATX tends to have a 40mm fan, not my favorite type of fan (noise).

On elongated PSUs, two of the dimensions are fixed. Measuring
the short dimensions, you would hope those dimensions are all
the same, everywhere. The "length" of the unit, can vary with
power output. (Even on ATX, a 1200W supply can be longer than a
600W supply.)

At one time, PSUs did not list the efficiency on the label.
Efficiency was poor (70% or less), and the heat used to pour out
of the fan opening. Now, they have 80%+ efficiency, and
they have "metal" ratings like "bronze" or "gold". One advantage
of the higher efficiency units, is not the savings on the
electrical bill, but the fan does not have to spin as fast
to keep them cool. And that means less noise. They have
managed, on some idling computers, that the Flex fan does not
have to spin at all. Run Prime95, and the fan spools up.

https://en.wikipedia.org/wiki/80_Plus # Contains colour scheme versus efficiency value

It's probably leaking caps that have affected the PSU. I had
an Antec that failed that way, and there were four capacitors
on +5VSB that had brown liquid stains on the top. And that's why
it packed in (computer tried to run, but CPU crashed due to bad
voltages).

*******

There is an outside chance, a motherboard failure could overload
a perfectly good PSU. We apply the same analysis there. Visual mobo inspection.
Examine tops of capacitors (cylinders with plastic sleeve). In addition,
examine the PCB around the CPU socket. Occasionally a plane-to-plane
short causes the PCB to turn brown from the heat. Your machine lacks
the brute force power to be burning in that fashion :-) If you had
a plane-to-plane short on VCore, the VCore circuit would just
calmly switch off, rather than roasting the mobo.

Before buying your supply, check how many peripheral cables the
new one has, and that it has enough power wiring for your disk
drives and so on. There isn't a lot of room for the mass of wires
coming out of the PSU, so they really can't afford to run too many
harnesses from there. But check anyway, as you don't want to discover
later that you can't, say, plug in your floppy any more.

Chances are, if it has a UK power plug, it's either a Universal or a 240V unit.
Some of the older designs, there is a red slider to match the
available mains voltage.

Paul

Let a homeless man fuck your ass,
then whistle out your anus!

Paul wrote:
> On 5/30/2023 7:03 AM, Ed Cryer wrote:
>> I have an old Acer Aspire X3990, used almost daily for 10+ years;
>> greatly modified to be a really good work-horse.
>> Suddenly I switch it on and instead of booting it whistles from the PSU.
>> I need a new PSU, but they're hard to find for such a heirloom.
>> Here's a picture of the PSU;
>> https://ibb.co/0hvpJkz
>> And here's a possible replacement;
>> https://tinyurl.com/2zrcs8j2
>>
>> I should think that PSU technology has advanced quite a bit.
>> I might be able to find something better.
>>
>> Any suggestions from the workbench?
>>
>> Ed
>
> Maybe that's a FlexATX ?
>
> They come up to 90% efficient and 600W.
> The previous generation would be somewhat less on both numbers.  80% 230W.
>
> You check the label with the output amperage listed, and
> then compare the replacement numbers to the original.
>
> For example, if the original was 12V @ 13A and the
> replacement is 12V @ 50A, it means both of them could
> manage to power a 13A load, and both would be suitable.
>
> if the replacement supply only made 12V @ 6A, it would
> presumably be too weak as a replacement.
>
> On modern computers, there isn't much that runs off -12V.
> That's why the current there is 0.3 amps. The RS232 serial
> port runs off that voltage.
>
> The -5V output was discontinued more than 20 years ago.
>
> The +3.3V, +5V, +12V are the mainstream outputs.
>
> The +5VSB is the "supervisor voltage" and powers the
> machine while it sleeps, and powers the machine enough
> so it can feel when the front button was pressed (soft ON/OFF).
> If the +5VSB has 3 amperes on offer, that's pretty generous.
> It does not offer a lot of amperes for charging an iPad via
> a USB connector, but it's otherwise a start at a power source.
>
> The FlexATX tends to have a 40mm fan, not my favorite type of fan (noise).
>
> On elongated PSUs, two of the dimensions are fixed. Measuring
> the short dimensions, you would hope those dimensions are all
> the same, everywhere. The "length" of the unit, can vary with
> power output. (Even on ATX, a 1200W supply can be longer than a
> 600W supply.)
>
> At one time, PSUs did not list the efficiency on the label.
> Efficiency was poor (70% or less), and the heat used to pour out
> of the fan opening. Now, they have 80%+ efficiency, and
> they have "metal" ratings like "bronze" or "gold". One advantage
> of the higher efficiency units, is not the savings on the
> electrical bill, but the fan does not have to spin as fast
> to keep them cool. And that means less noise. They have
> managed, on some idling computers, that the Flex fan does not
> have to spin at all. Run Prime95, and the fan spools up.
>
>    https://en.wikipedia.org/wiki/80_Plus          # Contains colour
> scheme versus efficiency value
>
> It's probably leaking caps that have affected the PSU. I had
> an Antec that failed that way, and there were four capacitors
> on +5VSB that had brown liquid stains on the top. And that's why
> it packed in (computer tried to run, but CPU crashed due to bad
> voltages).
>
> *******
>
> There is an outside chance, a motherboard failure could overload
> a perfectly good PSU. We apply the same analysis there. Visual mobo
> inspection.
> Examine tops of capacitors (cylinders with plastic sleeve). In addition,
> examine the PCB around the CPU socket. Occasionally a plane-to-plane
> short causes the PCB to turn brown from the heat. Your machine lacks
> the brute force power to be burning in that fashion :-) If you had
> a plane-to-plane short on VCore, the VCore circuit would just
> calmly switch off, rather than roasting the mobo.
>
> Before buying your supply, check how many peripheral cables the
> new one has, and that it has enough power wiring for your disk
> drives and so on. There isn't a lot of room for the mass of wires
> coming out of the PSU, so they really can't afford to run too many
> harnesses from there. But check anyway, as you don't want to discover
> later that you can't, say, plug in your floppy any more.
>
> Chances are, if it has a UK power plug, it's either a Universal or a
> 240V unit.
> Some of the older designs, there is a red slider to match the
> available mains voltage.
>
>    Paul

I'd like to find the best PSU available to replace this dud one, and do
the job myself.
And if there's a residual problem thereafter, I'll maybe seek
professional help.
I have a Currys/PC World store just down the road, and I called in to
see what they suggested. I take the box to them, pay 60 GBP, they
examine it and let me know what needs doing, I say ok and pay for all
parts used. Well, I've never talked to anyone in the repair shop, but if
they're anything like the gormless sales assistants I meet, then "No
sirree!".
So, I'm wanting the best PSU I can get.
Ed

On 5/30/2023 1:41 PM, Ed Cryer wrote:
> Paul wrote:
>> On 5/30/2023 7:03 AM, Ed Cryer wrote:
>>> I have an old Acer Aspire X3990, used almost daily for 10+ years; greatly modified to be a really good work-horse.
>>> Suddenly I switch it on and instead of booting it whistles from the PSU.
>>> I need a new PSU, but they're hard to find for such a heirloom.
>>> Here's a picture of the PSU;
>>> https://ibb.co/0hvpJkz
>>> And here's a possible replacement;
>>> https://tinyurl.com/2zrcs8j2
>>>
>>> I should think that PSU technology has advanced quite a bit.
>>> I might be able to find something better.
>>>
>>> Any suggestions from the workbench?
>>>
>>> Ed
>>
> I'd like to find the best PSU available to replace this dud one, and do the job myself.
> And if there's a residual problem thereafter, I'll maybe seek professional help.
>
> I have a Currys/PC World store just down the road, and I called in to see what they
> suggested. I take the box to them, pay 60 GBP, they examine it and let me know what
> needs doing, I say ok and pay for all parts used. Well, I've never talked to anyone
> in the repair shop, but if they're anything like the gormless sales assistants I meet,
> then "No sirree!".
>
> So, I'm wanting the best PSU I can get.
>
> Ed

It depends on your definition of "best".

At the bottom of the first item (made by Enhance), it says "Sold out" at the bottom.
This might be the Enhance retail version.

https://www.geeekstore.com/shop/enhance-enp-7660b-600w-black-flex-atx-modular-power-supply/

SilverstoneTek may be buying those OEM from Enhance, and charging yet another $100
for the privilege. Silverstone badges this as the FX600. Chances are it is built
on the same "platform", with minor component changes (like the details of how
the wires are connected to it).

https://www.reddit.com/r/sffpc/comments/s0v7ks/new_600w_flex_atx_psu_from_silverstone/

And as they note in the Reddit, the issue is the fan curve, and whether it
unnecessarily sounds like a pig or not. The *only* reason for buying a PSU
like this, is with the very light load your PC guts will place on it,
it has the potential to be pretty quiet.

I'm just surprised to be seeing "ball bearing" fan motors, when other
companies have FDB motors and other kinds of quieter fans on them (SSO maybe).
If one of those fans runs at 6000RPM or higher, I would not want to be
in the same room with it.

Anything which is not "ATX", I would be checking all dimensions, lips and
edges and stuff sticking out, before buying. And try to understand whether
the wire exit angle at the end of the unit is workable in a small space.
The Enhance claims to be using silicone wire, which may or may not be
an advantage. Basically, wire is wire, and to carry 50 amps at 12V, they
can't exactly be using 26ga wire. The ATX12V 2x2 or 2x4 could be carrying
a bit of current, with a modern high-end Intel CPU during turbo (28 or 56
second "burst" of turbo that warms things up). That can be on the order
of 200W. A 2x2 ATX12V is rated 144W, so to do an Intel Turbo on a 12th
gen would be a 2x4 connector.

The motherboards today would use a 24 pin main connector. It has four
wires more than the old 20 pin. One of the extra wires is a yellow one.
This carries 12V. Having two yellow wires on the main connector, gives
12V @ 12A capability, and that is used for PCI Express slots. (My
1050Ti video card, draws all its power from the PCI Express slot, and
that is 12V @ 5A approximately while running Furmark. No, that's not
a very good video card. It's what passes for a cheap video card.)

There is a connector near the CPU, and that's the ATX12v. On a 2x2 square
connector (with unique keying pattern so it only inserts one way), that
ATX12V has two yellow wires and 12V @ 12A capability. If instead the
motherboard is made with a 2x4 connector, there are four yellow wires on
one of those and 12V @ 24A capability for an Intel turbo run.

ATX12V 2x4 connectors usually consists of two 2x2 halves, with a "joint
or rib" that aligns the two halves. If used in 2x4 config, you have to squeeze
the two halves together, while pressing it into the socket.

If an ATX12V 2x4 is only being used in 2x2 mode (as only a 2x2 connector is
available on the motherboard), then one half of that connector is inserted
and the other half remains floating in mid-air. The two halves do not have
the same "shape" in their shrouds, so only one of the two halves will insert
and it only inserts one way (do not force it, check before beating the piss
out of it!).

Other connectors and looms, would include a PCI Express for a video card.
They could probably manage an 8 pin PCI Express, which would split into a
2x3 + 1x2. You use the 2x3 section on a video card with 2x3. You squeeze
the two bits together and insert 2x4 total, if the video card had a 2x4
connector. One PCI Express connector carries a bit more power than the other.

Most all of these references, are for computers with much higher consumption
than yours. Chances are, you don't have a video card with a separate PCI Express
connector on the end of it. And your ATX12V is just a 2x2 one. But I wanted
to explain some possible wire termination schemes on a 600W supply, and why
a person would be using them.

If a PC used the entire 600W of DC power from the PSU, the computer case
would be warmer than an oven inside. The "case cooling equation" would call
for several 35CFM case cooling fans. And again, I doubt your PC sounds like
a hoover and is somewhat subdued on the noise front. Your PC won't be using
the 600W, won't be like a toaster.

The 600W supply, does not hurt anything. You would not be at the absolute
highest efficiency point of the power curve. Your PC consumption is below
that point. You don't really care whether the PSU is 92% efficient
or 89% efficient. Just that the fan stay quiet and that's the only
reason for buying such a thing. You are getting Japanese caps and GaN
semiconductors.

GaN (according to this), can be made on a silicon carbide substrate,
even though the lattice does not match.

https://en.wikipedia.org/wiki/Gallium_nitride

Whereas LEDs are made with GaAs.

https://en.wikipedia.org/wiki/Gallium_arsenide

so who can say how expensive the GaN are to make. The boule for it,
might not be the same as the one for GaAs. The boule is what it looks
like, before it is sawed into wafers.

https://www.sciencephoto.com/media/442053/view/gallium-arsenide-boule

Paul

Ed Cryer <ed@somewhere.in.the.uk> wrote:

> I have an old Acer Aspire X3990, used almost daily for 10+ years;
> greatly modified to be a really good work-horse.
> Suddenly I switch it on and instead of booting it whistles from the PSU.
> I need a new PSU, but they're hard to find for such a heirloom.
> Here's a picture of the PSU;
> https://ibb.co/0hvpJkz
> And here's a possible replacement;
> https://tinyurl.com/2zrcs8j2
>
> I should think that PSU technology has advanced quite a bit.
> I might be able to find something better.

You don't say the PSU doesn't work. You only mention it whistles. Have
you tried blowing canned air through the grills in the PSU? Take off
the side panel, blow air into the back of the PSU, and then blow through
the grill inside. Could be just some debris buildup that makes the
whistle noise. Could also be the fan inside the PSU. Unplug the power
cord from the PSU, remove the PSU (or detach from case for screws, and
let dangle on wire harness to eliminate having to remember how to plug
it all back together), open the PSU case (it has screws), and use an ear
swab to swipe clean the fan blades. While it is open, blast the
internals with canned air again. Put the PSU back together, remount in
case, and retest. Make sure no cables, especially ribbon cables, are
blocking the intake grill on the PSU inside the case.

Since you'll have the case open, you sure the whistling comes from the
PSU fan, and not the CPU or GPU fans? While it's open, use canned air
to dust out the internals, especially the heatsinks. You can use swabs
on those fan blades, too.

When blowing air through a fan, put your finger on the hub, or use a
swab, to prevent the blade from spinning when unpowered.

If you power on the computer, but it doesn't power on, but the "whistle"
you hear is actually a high-pitched whine, and you're sure the whine
comes from the PSU, yep, replace it. A Google search on "aspire x3990
psu" finds many candidates for replacement for about $50.

https://www.google.com/search?q=aspire+x3990+psu

Some are listed at ebay.com. If you have a verified Paypal account, you
get Buyer Protection which has them refund an item if the seller doesn't
atone for their mistake.

https://www.ebay.com/sch/i.html?_nkw=aspire%20x3990%20power%20supply

Use the filters on price range, condition, shipping location, and so on
for how you want to throttle which ads match on your criteria. There
will be a sticker on the PSU to let you match a replacement on the same
wattage replacement.

The motherboard isn't very adaptable (2 memory slots, 1 PCIe x16 slot
likely for video card, and 1 PCIe x1 slot for piddly stuff, like a
modem), so I'm not sure how much you could have "modified" the setup to
be a "work-horse". My guess is you're using the integral video logic in
the CPU (Intel HD 2000 in the Intel i5) instead of a separate video
daughtercard. Comes with 4GB RAM installed, and the 2 slots let you add
up to another 4 GB for 8 GB total. The extra RAM will consume more
power, but whatever wattage rating you have currently for the old PSU
was likely capable of handling the extra RAM. However, your pic shows
the RAM slots are empty. Just how has the X3990 been "greatly
modified"? Is anything plugged into the PCIe 2.0 x1 or x16 mobo slots?

Yes, you can find later PSUs that are better, like more efficient, have
2 fans instead of 1, intake is fresh/cooler outside air instead of
preheated interior air, have more power, and so on, but you're
restricted to the physical dimensions of the old specialty format of the
Acer PSU. Unless you actually plugged in a video card with more VRAM
and faster GPU having it consume more power (but does not require a
separate power connection to the mobo, so just the PCIe slot's power
contacts are sufficient), you might want to bump up from the old 200W
Acer PSU to a 300W model provided the physical dimensions are the same.
You could get a different case into which you transplant the mobo to let
you put in standard sized PSU, but by then you might as well as start
putting aside money for a whole new build.

VanguardLH wrote:

> You don't say the PSU doesn't work. You only mention it whistles. Have
> you tried blowing canned air through the grills in the PSU?

Or it could be coil whine, does the noise change under load? or when
e.g. dragging windows around the screen?

VanguardLH wrote:
> Ed Cryer <ed@somewhere.in.the.uk> wrote:
>
>> I have an old Acer Aspire X3990, used almost daily for 10+ years;
>> greatly modified to be a really good work-horse.
>> Suddenly I switch it on and instead of booting it whistles from the PSU.
>> I need a new PSU, but they're hard to find for such a heirloom.
>> Here's a picture of the PSU;
>> https://ibb.co/0hvpJkz
>> And here's a possible replacement;
>> https://tinyurl.com/2zrcs8j2
>>
>> I should think that PSU technology has advanced quite a bit.
>> I might be able to find something better.
>
> You don't say the PSU doesn't work. You only mention it whistles. Have
> you tried blowing canned air through the grills in the PSU? Take off
> the side panel, blow air into the back of the PSU, and then blow through
> the grill inside. Could be just some debris buildup that makes the
> whistle noise. Could also be the fan inside the PSU. Unplug the power
> cord from the PSU, remove the PSU (or detach from case for screws, and
> let dangle on wire harness to eliminate having to remember how to plug
> it all back together), open the PSU case (it has screws), and use an ear
> swab to swipe clean the fan blades. While it is open, blast the
> internals with canned air again. Put the PSU back together, remount in
> case, and retest. Make sure no cables, especially ribbon cables, are
> blocking the intake grill on the PSU inside the case.
>
> Since you'll have the case open, you sure the whistling comes from the
> PSU fan, and not the CPU or GPU fans? While it's open, use canned air
> to dust out the internals, especially the heatsinks. You can use swabs
> on those fan blades, too.
>
> When blowing air through a fan, put your finger on the hub, or use a
> swab, to prevent the blade from spinning when unpowered.
>
> If you power on the computer, but it doesn't power on, but the "whistle"
> you hear is actually a high-pitched whine, and you're sure the whine
> comes from the PSU, yep, replace it. A Google search on "aspire x3990
> psu" finds many candidates for replacement for about $50.
>
> https://www.google.com/search?q=aspire+x3990+psu
>
> Some are listed at ebay.com. If you have a verified Paypal account, you
> get Buyer Protection which has them refund an item if the seller doesn't
> atone for their mistake.
>
> https://www.ebay.com/sch/i.html?_nkw=aspire%20x3990%20power%20supply
>
> Use the filters on price range, condition, shipping location, and so on
> for how you want to throttle which ads match on your criteria. There
> will be a sticker on the PSU to let you match a replacement on the same
> wattage replacement.
>
> The motherboard isn't very adaptable (2 memory slots, 1 PCIe x16 slot
> likely for video card, and 1 PCIe x1 slot for piddly stuff, like a
> modem), so I'm not sure how much you could have "modified" the setup to
> be a "work-horse". My guess is you're using the integral video logic in
> the CPU (Intel HD 2000 in the Intel i5) instead of a separate video
> daughtercard. Comes with 4GB RAM installed, and the 2 slots let you add
> up to another 4 GB for 8 GB total. The extra RAM will consume more
> power, but whatever wattage rating you have currently for the old PSU
> was likely capable of handling the extra RAM. However, your pic shows
> the RAM slots are empty. Just how has the X3990 been "greatly
> modified"? Is anything plugged into the PCIe 2.0 x1 or x16 mobo slots?
>
> Yes, you can find later PSUs that are better, like more efficient, have
> 2 fans instead of 1, intake is fresh/cooler outside air instead of
> preheated interior air, have more power, and so on, but you're
> restricted to the physical dimensions of the old specialty format of the
> Acer PSU. Unless you actually plugged in a video card with more VRAM
> and faster GPU having it consume more power (but does not require a
> separate power connection to the mobo, so just the PCIe slot's power
> contacts are sufficient), you might want to bump up from the old 200W
> Acer PSU to a 300W model provided the physical dimensions are the same.
> You could get a different case into which you transplant the mobo to let
> you put in standard sized PSU, but by then you might as well as start
> putting aside money for a whole new build.

I'll have a go with cleaning the PSU as you suggest. Enough dust gets
into the CPU heatsink (which I clean regularly), but I've never thought
to clean the PSU.

The box doesn't boot. I switch it on and the PSU whistles; and that's all.

My modifications are;
Large SSD.
DVD-writer.
Memory 8GB.
All been in situ for several years, and working excellently.

Thanks again, pal.

Ed

Ed Cryer wrote:

[snip]

>
> I'll have a go with cleaning the PSU as you suggest. Enough dust gets
> into the CPU heatsink (which I clean regularly), but I've never thought
> to clean the PSU.
>
> The box doesn't boot. I switch it on and the PSU whistles; and that's all.

This may be because the motherboard has failed.

Unplug all the connectors from the PSU (except the incoming mains),
identify the wire that needs to be grounded to cause it to power up,
then measure whether the output voltages are present and correct. I
take it you do have a suitable multimeter?

Confirm this by borrowing a standard PSU (with the correct output
connectors)and plug it into the motherboard, leaving the PSU propped
outside the case. Does the PC start up, or does that PSU also scream?

If a replacement standard PSU gets everything working, then it will be
worth buying the correct replacement to go inside the housing

--
Graham J

On 5/31/2023 4:36 AM, Ed Cryer wrote:

> I'll have a go with cleaning the PSU as you suggest. Enough dust gets into the CPU heatsink
> (which I clean regularly), but I've never thought to clean the PSU.
>
> The box doesn't boot. I switch it on and the PSU whistles; and that's all.
>
> My modifications are;
> Large SSD.
> DVD-writer.
> Memory 8GB.
> All been in situ for several years, and working excellently.
>
> Thanks again, pal.
>
> Ed

That could be the +5VSB. Which typically does not go over
3 amperes, has current limiter function, and powers the USB ports.

At one time, on older computers, there was a jumper plug where you
could power USB ports off +5V (USB port only powers, when PC running),
or for wake-up USB ports, you could run them off +5VSB (which is
powered all the time).

Later designs, they removed the header, and the USB ports were
only powered off +5VSB.

This means an overload on USB, could cause the PSU to whistle.

The +5VSB at one time, was quite inefficient and kicked out a bit
of heat. More modern PSU use an SMPS for the supervisory voltage,
which is more efficient. But it still has an overcurrent detection.

the +5VSB is a single wire on the main motherboard 24 pin cable.
If you have a clamp-on DC ammeter, you can clamp it around the
+5VSB wire and measure the current. But while your box is whistling,
you can't really make much of a measurement. The +5VSB is unlikely to be
making the full five volt value at the moment.

I have at least one spare PSU, and I just swap them in when there is trouble.
On my dead P4, swapping the PSU did nothing for me, confirming the ICH5
had blown up. It was supposed to die, when exposed to ESD, but it seems
to have died in its sleep :-) That's two motherboards that died on me
and no swollen caps either, on either of them.

*******

If you want a quick debug step, with the PC not started, unplug
all external USB and PS/2 connectors, and then switch on at the back
of the PC. And see if it whistles with just the motherboard for company.
Removing those connectors, is intended to reduce the loading on +5VSB
and perhaps... it will stop whistling.

When my Antec with the bad caps died, it did not die outright. It
was making a little puff of grey smoke, at startup, as the first hint of
bad caps. But later, the PC would crash at BIOS level, which is
a sign the output voltages were no longer normal.

Paul

Ed Cryer <ed@somewhere.in.the.uk> wrote:

> I'll have a go with cleaning the PSU as you suggest. Enough dust gets
> into the CPU heatsink (which I clean regularly), but I've never thought
> to clean the PSU.
>
> The box doesn't boot. I switch it on and the PSU whistles; and that's all.
>
> My modifications are;
> Large SSD.
> DVD-writer.
> Memory 8GB.
> All been in situ for several years, and working excellently.

Tis possible the dust buildup inside the PSU is the culprit, but also
possible the PSU has been damaged from overheating. Typically the
intake air into the PSU is pre-heated (CPU, memory, drives, mobo, etc).
The PSU isn't 100% efficient, so it generates heat, too. ATX PSUs are
typically box shaped, but the ITX PSU you have is elongated. That setup
uses a mini-ITX motherboard and the ITX PSU to reduce size.

Comparison of mobo sizes:
https://upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Comparison_ATX_%C2%B5ATX_DTX_ITX_mini-DTX.svg/330px-Comparison_ATX_%C2%B5ATX_DTX_ITX_mini-DTX.svg.png
https://en.wikipedia.org/wiki/Mini_ATX

After removing the side panel from the case, get a flashlight to watch
the PSU fan. Press the power button, and check if the fan spins or not,
if it jiggles but doesn't spin (siezed fan), or if it never moves. With
the PSU case dismantled, you can flick a fan blade with your finger. If
it halts very quickly (doesn't spin more than once), its bearing is
shot. A good fan won't spin many times when you flick its blade with
your finger, but it should spin. You can also sometimes feel a bad
bearing by slowly rotating the fan using a finger. With a bad bearing,
you might feel a bit of resistance at the bad spot in rotation. If the
fan is bad, likely you can replace the fan, but may need some solder
w/rosin core and heatshrink tubing to snip the wires to the fan, and
splice in the new fan. If you use electrical tape instead of heatshrink
tubing to cover the wire splices, use a cable/zip tie around the tape
since it will unwrap over time.

From some pics of that PSU, there is a voltage select switch (red) at
the back near where the power cord plugs into the PSU. Even if it seems
to be at the correct position to match the input voltage, I would flip
it to the other position, and then back. Make sure it is solidly into
the indent for the correct position, and flipping the switch also cleans
its contacts.

After dusting out the mobo, and CPU and heatsink, and dusting the PSU by
blowing through the case grills, if you get to dismantling the PSU to
dust better inside of it, take a look inside to see if you can see a
fuse. Often, instead of a fuse holder, there is just a couple of clips
soldered into a PCB into which a fuse is pushed. However, sometimes the
fuse is just soldered onto the PCB (it has leads soldered onto the ends
of the fuse, and those leads are soldered into the PCB).

Does this PSU have a power brick in its power cord? That is, does the
power cord that plugs into the wall outlet go to a brick, and then
another cord runs from the brick to the PSU? If so, and if the output
voltage is labeled on the brick, check the output voltage with a
multimeter. Make sure the cord that plugs into brick is fully seated,
like unplug and replug that cord into the brick. Some folks will do a
lot of work without checking power is reaching the PSU, like they kick
the plug that is under their desk, or the brick hangs from the desk
instead of sitting on the floor. I hate power bricks. I fabricate a
set of wire ties to eliminate the cords walking out of the brick: two
loose on each cord on each end of the brick, loop a cable tie between
the two loose ones on the cords, on each side of the brick, and tighten
down the ties as a bail to pull on the cords into the sockets in the
brick. Typically the plugs are too tight into the brick to use hot-melt
glue. Super glue doesn't work on nylon in a somewhat flex connection.
Bricks are often found with laptops to reduce size of the laptop (but
then the size difference is consumed by the brick which is external),
but yours is a desktop.

While we've been focused on the PSU, it's possible the problem is on the
mobo. There is logic on the mobo that tells the PSU if it powers up or
not. With the old AT-style PSUs, the power switch was hardwired into
the PSU (it was a switch on the front of the case that was wired to the
PSU). With ATX-style PSUs, the power switch goes to the mobo, and logic
on the mobo tells the PSU when to power up. While the power cord is
attached to the PSU, and even with the computer powered down, the PSU
still generates a 5V STBY (5 VDC standby output voltage) in the 24-pin
harness from PSU to mobo. That powers the 3VDC "power-on" logic on the
mobo. As a test, with the 24-pin PSU harness connected to the mobo, you
could short the Pwr-On lead (green wire) to ground. That lead dropping
to zero volts is what tells the PSU to power up; else, it floats high.

https://www.lifewire.com/thmb/se_V_Mh6qrGZHtG5hGu3YQFVnRA=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/atx-24-pin-12v-power-supply-pinout-2624578-bd809482596447b7afa7c63232719560.png

Pin 15 is PS-ON, and shorting to ground will turn on the PSU. This line
must be kept low to keep the PSU turned on; else, the only output
voltage from the PSU is the 5VSB line (pin 9) to power the on-board mobo
logic for this line. If the PS-ON line doesn't go low, the PSU won't
come on. When I do this test, I get a sewing needle to jab into the
backside of the 24-pin connector to contact the female pin in there, and
use a jumper cable (alligator clips on each end) to connect the needle
to a ground point. You could use another sewing needle in any of the
GND leads (pins 3, 5, 7, 15, 17, 18, 19, 24) in the 24-pin connector.
If you don't have a jumper wire, you could try jamming sewing needles
into pin 16 (PS-ON) and a GND lead next door (pin 15 or 17), and
crossing the needles to touch each other to make the short across pins
(PS-ON to GND). Once PS-ON is shorted to GND, the PSU fan should spin.

Tis possible the system is overloaded. PSUs wan in capacity over time.
No matter what is their rated power output, that lessens over time.
What the PSU was capable of handling early on may become too much later.
I forgot where I read the tested reduction, but recall it was about 5%
capacity loss per year for typical-grade hardware, less for higher
quality hardware. Expect 20% capacity loss over its lifetime (which
cheap PSUs having a shorter lifetime). As the components inside the PSU
age, they become less efficient which means less delivered power and
more generated heat. A reduction in input voltage to the PSU causes
less efficient conversion, and more heat. Dust buildup reduces thermal
transfer away from components in the PSU decreasing efficiency which
generates even more heat. Running a PSU at its real maximum capacity
(which is often less than its rated capacity, especially for cheap PSUs)
will reduce efficiency (which is not linear to the load). Running a
sustained total load of 75% of its rating will reduce capacity. Most
degradation is from high temperatures, and why you need to dust out your
computer, heat sinks, memory modules, video card, and the PSU. I've
seen folks try using estimators on how much power is needed from the PSU
based on what loads it will supply and efficiency of the PSU, and then
buy a PSU that barely exceeds that power draw. To hell with that. I
figure out what might be the power draw if everything I could attach to
the PSU were populated, like when later upgrading the system, and then
double that for what size of PSU to get. If the computations show a
400W PSU is sufficient, I get an 800W PSU, or bigger depending on the
depth of my pocket at the time. Getting a PSU "to size" is a mistake
that you'll make once. Guess what happens to your power computations
when you later decide to add a 200W video card? You'll spend again to
get a better PSU. Pre-builts are designed to their specifications, not
on how you might upgrade them later. They sell by spec, not quality.

Also, be aware that the ratings on PSU is often for non-sustained
maximums; i.e., they over rate their capacity. Some PSUs are under
rated, but many are over rated. The protections are often over rated,
too. Some PSUs will cut out when overloaded, but some will literally
burn up. When you open the PSU, and after dusting it out, use your nose
to determine if the PSU burned up. In pre-builts, typically the PSU is
the minimum needed for the factory config, and not much leeway for an
enlarged power load (and their power factor curve has a much sharper
drop at the max load end so efficiency drops a lot so more heat), and
longevity isn't that long, like about 5 years, or just enough to get
past the warranty period. There are a lot of crappy PSUs out there, and
many won't meet or exceed their ratings shown on a label on the PSU.

Another test would be to disconnect the 24-pin PSU connector from the
mobo, and short PS-ON (pin 16) in the connector to GND (pin 15 or 17) in
the connector (the pins will be exposed to make contacting them easier).
However, some PSUs will still not power on unless there is some power
draw. That is, even with PS-ON shorted to ground, the PSU wants to see
something drawing power from it. So, leave a drive connected to the PSU
wiring harness. The drive needs to power up to draw power, so an
optical drive won't do. Leave a spinner or SSD attached. After
shorting PS-ON to ground, the PSU fan should spin.

Anyone wanna smell my ass for $130.88?

Ed Cryer wrote:
> I have an old Acer Aspire X3990, used almost daily for 10+ years;
> greatly modified to be a really good work-horse.
> Suddenly I switch it on and instead of booting it whistles from the PSU.
> I need a new PSU, but they're hard to find for such a heirloom.

> Ed

Primarily, two types of whine from a PSU.
Coil and Fan.
One vibration, the other rotational.
- the former is electrical, the latter mechanical.

--
....w¡ñ§±¤ñ

On 01/06/2023 19:52, ...winston wrote:
> Ed Cryer wrote:
>> I have an old Acer Aspire X3990, used almost daily for 10+ years;
>> greatly modified to be a really good work-horse.
>> Suddenly I switch it on and instead of booting it whistles from the PSU.
>> I need a new PSU, but they're hard to find for such a heirloom.
>
>> Ed
>
> Primarily, two types of whine from a PSU.
> Coil and Fan.
>  One vibration, the other rotational.
>  - the former is electrical, the latter mechanical.

FYI - https://chat.openai.com/share/a7ea271a-ac43-445b-aab4-10d6ba89b1aa

On 01/06/2023 20:51, David Brooks wrote:
> On 01/06/2023 19:52, ...winston wrote:
>> Ed Cryer wrote:
>>> I have an old Acer Aspire X3990, used almost daily for 10+ years;
>>> greatly modified to be a really good work-horse.
>>> Suddenly I switch it on and instead of booting it whistles from the
>>> PSU.
>>> I need a new PSU, but they're hard to find for such a heirloom.
>>
>>> Ed
>>
>> Primarily, two types of whine from a PSU.
>> Coil and Fan.
>> ��One vibration, the other rotational.
>> ��- the former is electrical, the latter mechanical.
>
>
> FYI - https://chat.openai.com/share/a7ea271a-ac43-445b-aab4-10d6ba89b1aa

I�m sorry to hear that. I found some options for you to consider. You
can purchase a*new genuine Acer/Gateway 220 Watt form factor computer
power supply*for your Acer Aspire X3990 fromlaptopparts.ca
<https://laptopparts.ca/products/new-genuine-acer-aspire-x3990-xc-105-xc100-xc600-computer-power-supply-220-watt>for
$99.98
<https://laptopparts.ca/products/new-genuine-acer-aspire-x3990-xc-105-xc100-xc600-computer-power-supply-220-watt>^1
<https://laptopparts.ca/products/new-genuine-acer-aspire-x3990-xc-105-xc100-xc600-computer-power-supply-220-watt>.
Another option is to buy a*100% new high quality Acer Aspire X3990
XC-105 XC100 XC600 Computer Power Supply 220 Watt PS
5221*fromonebattery.co.uk
<http://www.onebattery.co.uk/acer-AC-adapter/AXC105-210561.htm>for an
unspecified price
<http://www.onebattery.co.uk/acer-AC-adapter/AXC105-210561.htm>^2
<http://www.onebattery.co.uk/acer-AC-adapter/AXC105-210561.htm>. You can
also purchase a*300w power supply*for your Acer Aspire X3990
fromebay.co.uk <https://www.ebay.co.uk/itm/350940679289>for an
unspecified price <https://www.ebay.co.uk/itm/350940679289>^3
<https://www.ebay.co.uk/itm/350940679289>.You can also check out the
official Acer UK online shop for*Batteries, Adapters, Cables and Power
Kits*for Acer
Devices<https://store.acer.com/en-gb/accessories/adapters-cables>^4
<https://store.acer.com/en-gb/accessories/adapters-cables>.

I hope this helps!

On 5/30/2023 4:03 AM, Ed Cryer wrote:
> I have an old Acer Aspire X3990, used almost daily for 10+ years;
> greatly modified to be a really good work-horse.
> Suddenly I switch it on and instead of booting it whistles from the PSU.
> I need a new PSU, but they're hard to find for such a heirloom.
> Here's a picture of the PSU;
> https://ibb.co/0hvpJkz
> And here's a possible replacement;
> https://tinyurl.com/2zrcs8j2
>
> I should think that PSU technology has advanced quite a bit.
> I might be able to find something better.
>
> Any suggestions from the workbench?

Ebay or Amazon or ??

On 6/1/2023 4:56 PM, Big Dick wrote:
> On 01/06/2023 20:51, David Brooks wrote:
>> On 01/06/2023 19:52, ...winston wrote:
>>> Ed Cryer wrote:
>>>> I have an old Acer Aspire X3990, used almost daily for 10+ years;
>>>> greatly modified to be a really good work-horse.
>>>> Suddenly I switch it on and instead of booting it whistles from the
>>>> PSU.
>>>> I need a new PSU, but they're hard to find for such a heirloom.
>>>
>>>> Ed
>>>
>>> Primarily, two types of whine from a PSU.
>>> Coil and Fan.
>>>   One vibration, the other rotational.
>>>   - the former is electrical, the latter mechanical.
>>
>>
>> FYI - https://chat.openai.com/share/a7ea271a-ac43-445b-aab4-10d6ba89b1aa
>
> I’m sorry to hear that. I found some options for you to consider. You
> can purchase a*new genuine Acer/Gateway 220 Watt form factor computer
> power supply*for your Acer Aspire X3990 fromlaptopparts.ca
> <https://laptopparts.ca/products/new-genuine-acer-aspire-x3990-xc-105-xc100-xc600-computer-power-supply-220-watt>for
> $99.98
> <https://laptopparts.ca/products/new-genuine-acer-aspire-x3990-xc-105-xc100-xc600-computer-power-supply-220-watt>^1
> <https://laptopparts.ca/products/new-genuine-acer-aspire-x3990-xc-105-xc100-xc600-computer-power-supply-220-watt>.
> Another option is to buy a*100% new high quality Acer Aspire X3990
> XC-105 XC100 XC600 Computer Power Supply 220 Watt PS
> 5221*fromonebattery.co.uk
> <http://www.onebattery.co.uk/acer-AC-adapter/AXC105-210561.htm>for an
> unspecified price
> <http://www.onebattery.co.uk/acer-AC-adapter/AXC105-210561.htm>^2
> <http://www.onebattery.co.uk/acer-AC-adapter/AXC105-210561.htm>. You can
> also purchase a*300w power supply*for your Acer Aspire X3990
> fromebay.co.uk <https://www.ebay.co.uk/itm/350940679289>for an
> unspecified price <https://www.ebay.co.uk/itm/350940679289>^3
> <https://www.ebay.co.uk/itm/350940679289>.You can also check out the
> official Acer UK online shop for*Batteries, Adapters, Cables and Power
> Kits*for Acer
> Devices<https://store.acer.com/en-gb/accessories/adapters-cables>^4
> <https://store.acer.com/en-gb/accessories/adapters-cables>.
>
> I hope this helps!

Of course you can buy stuff like that.

You can also swap in a temporary supply, and
verify that everything works before doing anything else.

And once the swap works, you can take the cover off the
duff power supply, and determine whether it can be fixed.
For example, one of the dead Antec supplies, I could change out
the four +5V output capacitors and the supply would undoubtedly
be "as good as new". This assumes capacitor juice does not get
all over the place and damage copper traces.

Like going to the doctor, there's a flowchart for how to proceed
and steps to do first.

*******

If taking a machine to the shop for work, I recommend pulling
the hard drive, and backing it up before taking the machine
to a computer store repair department. There have been reports
in the past, of computer shops erasing the hard drive and
reinstalling the OS, when there was nothing on the ticket
suggesting such a thing was necessary or had anything to do
with the job. And by erasing customer data files, the customer
then has nothing.

By making a backup of the drive, it does not matter what the
shop does to the drive, in the process of doing repair work,
you can always restore from backup later if not satisfied
with what was done (or "over-done"). On a desktop, you can plug
the drive from the duff computer, into the working computer, and
do your backup of it.

The only level of unexpected outcome worse than that, is
you take a computer to a computer store, two days later, the
computer store goes bankrupt, the computer is "trapped inside
the store", and you can't get it back. For example, the computer
store I use here, I would not take a computer for repair, because
I really don't know how solvent the chain is. We've had computer
chains go bankrupt here before, without warning. It just seems
to be a business "built on bankruptcy". At the current time, my
computer store has the "how is this store still running" look to it.

Paul