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Did I buy a bad interposer?

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First post, by failuresuccess

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Hi all,

I just got my hands on what I thought was a good deal for a 486 interposer by Aries. I couldn't get it working on my IBM PS/1 but it turns out it looks like my PS/1's caps may finally need replacing but that's a separate topic. In the effort of troubleshooting my PS1 I noticed two pins appear to be missing from the interposer. If I'm reading the diagram correctly at the following link it would appear pins A1 and A17 are missing.
http://ps-2.kev009.com/eprmhtml/eprmx/h12203.htm

Are these missing pins critical or can the cpu function without them? If not, would it be possible to get the correctly sized pins and solder them back into place?

Please note the image that has two red arrows pointing to the missing pins, the white blobby dot is the corner of the cpu you align to the notch/triangle.

As always, any insight in greatly appreciated!

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Reply 1 of 5, by debs3759

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They look important to me, as neither of those pins is duplicated anywhere, and one of them is a data pin.

See my graphics card database at www.gpuzoo.com
Constantly being worked on. Feel free to message me with any corrections or details of cards you would like me to research and add.

Reply 2 of 5, by Horun

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Huh looks like the D20 and Ahold pins are missing. The corner pin by the key pin is D20 and required as is the other....
yes you should be able to solder in a replacement (though you need a good stiff wire/borrowed pin).
Are you sure your PS/1 will accept the interposer and cpu ?

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 3 of 5, by failuresuccess

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Horun wrote on 2023-02-14, 01:39:

Huh looks like the D20 and Ahold pins are missing. The corner pin by the key pin is D20 and required as is the other....
yes you should be able to solder in a replacement (though you need a good stiff wire/borrowed pin).
Are you sure your PS/1 will accept the interposer and cpu ?

That's promising to hear, I'll have to try and get a replacement pin.

I believe it should work on the ps/1 but it'll clock down to a lower speed as the bus only runs at 25mhz. I actually have (had) it running on a Kingston AMD 586 cpu, pictured below.

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Reply 4 of 5, by Disruptor

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Horun wrote on 2023-02-14, 01:39:

Huh looks like the D20 and Ahold pins are missing. The corner pin by the key pin is D20 and required as is the other....
yes you should be able to solder in a replacement (though you need a good stiff wire/borrowed pin).
Are you sure your PS/1 will accept the interposer and cpu ?

You may try to solder the end of a classic resistor. It should be stiff enough. As long as it fits into the socket itself 😉

Reply 5 of 5, by kaputnik

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You could try pushing the broken pins out from the bottom/broken side with a heated soldering iron, preferably with a narrow conical tip, and steal pins from a precision DIP socket to replace them with. Clean up the holes in the PCB from solder residues, carefully push the new pins in from the top side with the soldering iron - take care to clean the tip thoroughly first, you don't want solder in the new pin's hole - and finish by redoing the solder joints to the PCB.

Replaced individual pins in DIP sockets that way with very good results a few times when I didn't have a replacement socket with the right number of pins at hand. Even if the additional PCB might complicate it a little bit, it should work with your interposer too.

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