Re: Looking for suggestions on what next to troubleshoot on a dead IBM ps/1 montherboard

Posted on 2023-02-27, 22:10

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'll have to see if I can figure out the trace, the pin for the surface mount chip has that trace on the underside of the board. That said perhaps I'm not being very clear, I can't even get the board to start with just the onboard 25MHz cpu with proper jumpering.

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Re: Looking for suggestions on what next to troubleshoot on a dead IBM ps/1 montherboard

Posted on 2023-02-27, 19:56

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That shouldn't be needed on this board unless something else has gone wrong. If I move jumper j25 to the topmost two pins that tells the board to use the overdrive socket. This behavior was working just fine a few weeks ago but now it doesn't matter what position it is in. If I remove the AM586 cpu …

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Re: Looking for suggestions on what next to troubleshoot on a dead IBM ps/1 montherboard

Posted on 2023-02-27, 18:06

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I went ahead and checked that and I'm not seeing any voltage so I'm guessing that's not the problem. You could check the reset signal c16 from what I understand reset should be present on boot then go down, I actually have this problem on one of my boards where reset is stuck on constant 5v which …

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Re: Looking for suggestions on what next to troubleshoot on a dead IBM ps/1 montherboard

Posted on 2023-02-27, 01:20

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Here's a picture of the whole mainboard, I believe it's in the 2155 family of IBM PS/1 motheboards. https://theretroweb.com/motherboards/s/ibm-ps … t2155a,-mt2168a

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Looking for suggestions on what next to troubleshoot on a dead IBM ps/1 montherboard

Posted on 2023-02-27, 01:18

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Evening all, I've got an IBM PS/1 486sx @ 25Mhz motherboard that recently started failing to post. It was working with the surface mount 25Mhz cpu and my 133Mhz AMD 586 cpu. I tried removing all the hardware and switching between CPUs and several sticks of ram. I've tried testing with one of those …

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Re: Did I buy a bad interposer?

Posted on 2023-02-14, 02:29

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

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 …

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Did I buy a bad interposer?

Posted on 2023-02-13, 22:16

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

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 …

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Re: Help me restore my childhood... computer

Posted on 2023-02-12, 02:41

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Evening all, So my PS/1 finally stopped booting all together, it never seems to get to a point to where it can post. I removed all the expansion cards, the hard drive, and floppy. I've also tried booting with the integrated cpu, two different amd 5x86 cpus, and different sticks of ram. No post beeps …

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Re: Help me restore my childhood... computer

Posted on 2022-03-05, 23:32

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Fan installed

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Re: Help me restore my childhood... computer

Posted on 2022-03-05, 19:52

by

by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I got a heat sink attached and so far so good. Even without a fan the cpu sits at 121f. Sim city 2000 proved to be pretty good keeping the cpu at 100%. I plan to attach a cpu fan later tonight to see what kind of temperature I get. Filename AF7E7601-7906-4FA8-9026-9943E7689F2A.jpeg File size 1.52 …

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Re: Help me restore my childhood... computer

Posted on 2022-03-04, 14:51

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That makes sense and I didn't even think about using a northbridge heatsink. That said though I went ahead and ordered a set along with some fans.

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Re: Help me restore my childhood... computer

Posted on 2022-03-04, 04:08

by

by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So after much stressing I managed to remove the fan from my Am5x86 using a chisel blade on an x-acto knife. After carefully working the blade under the fan the majority of it broke free. Unfortunately a portion remained stuck to the cpu. I spent about an hour painstakingly scraping the plastic off …

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Re: Help me restore my childhood... computer

Posted on 2022-03-01, 14:23

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So good news, bad news. I got my hands on a DTC - Data Technology - 2280-E controller card off ebay. However, I can't for the life of me get the card to work and I suspect it may be because of the motherboard's bios. I can disable the secondary hard drive entry and both floppy drive entries in the …

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Re: Help me restore my childhood... computer

Posted on 2022-02-25, 04:26

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you have tried multiple drives and cables then its very likely the controller on the motherboard has issues, possibly a cap has died or the control IC has internal issues. Its not uncommon for IO stuff to fail on old hardware, usually its the IDE controller that fails first. That's what I was …

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Re: Help me restore my childhood... computer

Posted on 2022-02-25, 04:20

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks all, I’ll give that a try to get the junk off. As for the floppy drive the motherboard can see it but when I try to access it in dos I immediately get “Data error reading drive A”. Ive tried 3 drives and 4 cables at this point. I’m guessing something on the motherboard has started to fail. …

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Re: Help me restore my childhood... computer

Posted on 2022-02-25, 02:26

by

by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks all, I’ll give that a try to get the junk off. As for the floppy drive the motherboard can see it but when I try to access it in dos I immediately get “Data error reading drive A”. Ive tried 3 drives and 4 cables at this point. I’m guessing something on the motherboard has started to fail. …

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Re: Help me restore my childhood... computer

Posted on 2022-02-23, 00:56

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So one positive update, I found a 52x cdrom and it plays nice with the cf card. No idea why my other cd and dvd drives didn’t want to cooperate.

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Re: Help me restore my childhood... computer

Posted on 2022-02-23, 00:50

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Well that doesn’t look good. I washed both sides last week and maybe I just missed it but does that look like corrosion near the floppy connector pins? I’m wondering if my growing floppy drive issue is because the solder joints are bad. Filename A583D8D8-9A47-47F6-A8EC-459458E94735.jpeg File size …

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Re: Help me restore my childhood... computer

Posted on 2022-02-22, 14:07

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'll see if I can encourage the floppy driver/controller to behave long enough to try today.

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Re: Help me restore my childhood... computer

Posted on 2022-02-22, 01:29

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by failuresuccess

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Updates! So I've got the computer up and running with DOS 6.22, a 52X cd drive, and a non PNP AWE32. Doom 1 and Wolf 3D both work and seem to play ok but Doom 1 is a bit slow with settings maxed out even with 32MB of ram. So I'm guessing the bigger CPU I have coming in should help. Now for the …

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