I have a Heathkit H8 which worked perfectly 3 years ago when I put it in storage.
Now, it's erratic and I see corrosion on the bus pins.
But even after cleaning with deoxit - there is a splotchy discoloration on the metal.
The pins are smooth - the deoxit got all the little bumps.
But will the discoloration affect performance? Is there a way to remove it?

I've already processed the 'hindsight is 20/20' route.
Not only did Heathkit NOT use the S-100 bus, they did NOT use gold. Sheesh.

On Thursday, July 28, 2022 at 2:21:46 PM UTC-5, john_c...@yahoo.com wrote:
> I have a Heathkit H8 which worked perfectly 3 years ago when I put it in storage.
> Now, it's erratic and I see corrosion on the bus pins.
> But even after cleaning with deoxit - there is a splotchy discoloration on the metal.
> The pins are smooth - the deoxit got all the little bumps.
> But will the discoloration affect performance? Is there a way to remove it?
>
> I've already processed the 'hindsight is 20/20' route.
> Not only did Heathkit NOT use the S-100 bus, they did NOT use gold. Sheesh.
Gold connectors are available.

Check with the heathkit group sebaceous.

Post there, they have continued to design H8 boards like IDE and SD support.

Originally the H8 didn't support CP/M because the boot rom is located at 0000H.

Randy

On 29/07/2022 05:21, john wrote:
> I have a Heathkit H8 which worked perfectly 3 years ago when I put it in storage.
> Now, it's erratic and I see corrosion on the bus pins.
> But even after cleaning with deoxit - there is a splotchy discoloration on the metal.
> The pins are smooth - the deoxit got all the little bumps.
> But will the discoloration affect performance? Is there a way to remove it?
>
> I've already processed the 'hindsight is 20/20' route.
> Not only did Heathkit NOT use the S-100 bus, they did NOT use gold. Sheesh.

You might try an art (aka pencil) eraser of the soft white variety.
Back in the day we used a commercial product called microscrub:

https://www.worthpoint.com/worthopedia/gpo-strowger-microscrub-contact-425225359

OTOH it could be a bit rough. A pencil eraser would be safer for
delicate things such as gold-plated contacts.

> Check with the heathkit group sebaceous.

https://groups.google.com/g/sebhc/about

On Friday, 29 July 2022 at 05:55:13 UTC+1, dxforth wrote:
> Back in the day we used a commercial product called microscrub:

Today's alternative are those glass fibre pencils I use one of them for contacts on cartridges/ISA cards etc, just take some care when you use them as they produce small pieces of fibreglass.

I wonder if any sort of cleaning will work on tinned pins. The solder is probably too soft to polish, and so soft that it absorbs particles from whatever you use to clean it - just making things worse. The SEBHC consensus is to replace with gold-plated pins.

Once you have cheap tin pins corroded and pitted unless there is a really good reason to save them, they need to be replaced.

That also applies to pins on chips. And yes, I have had chips I repaired with wires because they were difficult if not impossible to replace.

Randy

On Thursday, July 28, 2022 at 12:21:46 PM UTC-7, john_c...@yahoo.com wrote:
> I have a Heathkit H8 which worked perfectly 3 years ago when I put it in storage.
> Now, it's erratic and I see corrosion on the bus pins.
> But even after cleaning with deoxit - there is a splotchy discoloration on the metal.
> The pins are smooth - the deoxit got all the little bumps.
> But will the discoloration affect performance? Is there a way to remove it?
>
> I've already processed the 'hindsight is 20/20' route.
> Not only did Heathkit NOT use the S-100 bus, they did NOT use gold. Sheesh.

I replaced all the tin connectors on my H8 last week. Bought a Hakko FR-301 and a bag of gold headers. Took about 3 hours. Problem solved.