Currently I am trying to revive my old 386 machine. I bought it some time ago. Unfortunately it was incomplete and seller didn't secure package well enough which cased some damage of plastic front and back panels. There was also a problem with depleted built-in batter of RTC module. Fortunately I …

Thanks. It in fact looks similar. DX-33 is there simply because I do not have anything better in my collection at this point. Board had some damage from battery acid spill, resulting in "keyboard error". Fortunately cleaning affected part of the board and resoldering socked resolved that problem. …

Does anyone of you is able to recognize this motherboard and/or can provide manual? Cache and CPU speed jumper settings are described, but not much else. Googling numbers from the backside didn't reveal anything useful. 🙁

Recently I bought new retro PC for my small collection - COMPAQ 386S/20. It was the beginning of the long series of misfortunes. Fortunately device was not expensive. It was sold as in "working condition", however lacking drives. First disaster: front panel of tha case had been destroyed in …

Some of my boards throw a 1314 when I forget to install RAM. As you can see on photos, there is RAM installed. Anyway, it not an issue that would have been resolved by shorting reset pins. ;) I made another observation: when board is turned on for the first time, it usually requires few resets to …

I began restoration of another vintage motherboard, this time Socket 3 486 model. As usual there was a sign spilled acid from VART battery. Fortunately corrosion was mild and localized. Battery was already removed by the previous owner. Aside the main problem that I will describe in a moment, there …

Ok, I was able to run memory test with few different programs. It turned out to be a protected mode fault. Now I noticed another issue. It looks like there was no cache at all. None of the programs is able to see it: I tried Checkit, CacheCheck and MemTest86+ 2.11.. I also can't locate cache related …

UPDATE: I found and patched two more broken traces leading to first cache chip. It didn't help. Any hints how to locate broken reset trace? :) EDIT: Board works. It turned out to be a power supply issue. I spotted some other problems while testing this board with Checkit. Board restarts itself after …

ISA RESET signal (B2 pin) should been connected directly to the CPU/Chipset RESET lines? It isn't. I also assume LT38C41 is strict, pin compatible equivalent of 8042/8242 chip and its 4th pin is RESET signal? There is no continuity, but it makes sense as it is active low.

Thanks for all the suggestions. I removed some elements nearby the CMOS battery. There are in fact some signs of corrosion. I will try to clean it with vinegar and then IPA, check continuities and tin traces. Is there a way to fin a trace that is most probably responsible for this issue? Is there …

Few weeks ago I bought old 386 motherboard on local auction site. It was described as "in working condition" by the seller, but after receiving order I found out it was repaired rather poorly. Damaged VARTA battery had been removed, but the area wasn't cleaned from the most of the corrosion. Few …

It's alive!

By the way, can you give me the values of the caps nearby the PSU connector ? :D The view is obscured by the PSU connector and memory slots. I has to slide a little mirror beneath them to be able to even see marked sides . :) I still can't place my phone anywhere closer go get better image. Maybe …

No problem, there it is :) https://www.vogons.org/viewtopic.php?p=854924#p854924 Thanks! I will test it. I hope v2.2 is compatible with v2.1 BIOS. By the way, I was able to google few photos of v2.2 version of this board with BIOS still in socket. The label on that chip clearly states "Award …

Hi there ! I just bought a lot of junk motherboards, and this is the "cleanest" one. It's a GMB-486UNP V2.1 (...) Edit: mobo seems identical to this one : https://www.vogons.org/viewtopic.php?f=46&t=60741#p679055 Recently my friend gave me nearly identical motherboard. The only difference is that …