Re: Original IBM EGA card repair thread
Posted on 2023-05-19, 07:53
One PCB trace on the back (behind U21) looks suspicious, test it for continuity. There are also some other scratches but those don't seem too bad.
Re: What motherboard do I have?
Posted on 2023-05-18, 22:43
Cache chips in bank 0 are inserted wrong, I think.
Re: Lucky Star 5I-VX2B video cards problems
Posted on 2023-05-04, 20:59
Are the Trident and Alicat confirmed working on another motherboard? Have you tried cleaning the connectors, pushing down the socketed chips (if any)? On the CL card there seems to be a problem with the green signal. Carefully check it for any missing or damaged parts. Maybe upload some close-up …
Re: P100 Hanging at "Updating ESCD"
Posted on 2023-01-27, 11:07
Just an idea, maybe you already did it the "right" way, but don't just copy the old chip, use instead a clean image downloaded from the net. I once had a board that got stuck at "Verifying DMI data pool..." because of a flash chip gone bad, and a 1:1 copy on a fresh chip behaved exactly the same. …
Re: BIOS corrupting itself
Posted on 2022-12-21, 23:47
Just an idea. BIOSes around that time started to store data (ESCD, DMI) inside the flash chip. Maybe the corruption happens because it tries to write something but it fails because of "Unknown flash type". Also (and I might be very wrong here), couldn't this "dual bios" be implemented by using two …
Re: Video card only displays red? (not defective VGA port) (Colorimage 59-6693-0007 Tseng ET4000AX 1MB)
Posted on 2022-11-01, 23:57
L4 and L5 (close to the VGA connector) really seem to be missing 😀
Re: Help with Octek Fox M 286 (broken chip)
Posted on 2022-10-26, 08:19
Heh, I'm sure it's easy for you but for me this is some kind of wizardry. Maybe I could have solved it by only focusing on this problem for 5 years straight :D I'm also sure that REDLED's dump is accurate, but it's more of a truth table for the chip, and how to get from that to the needed .JED file …
Re: What to do about a Socket 462/A motherboard with a broken socket?
Posted on 2022-10-25, 21:50
How was the old cooler attached? Using the mounting holes around the socket? If you still have it (and the mounting hardware) is it possible maybe to exchange the fan for a modern/silent one? Also, there are plenty of Socket A coolers that engage all three hooks on both sides. If you don't go for a …
Re: Another 486 no-POST
Posted on 2022-10-25, 21:44
Fiddled a little with the oscilloscope around the board today. Noticed that after some resets there was activity on the EPROM data/address lines, all except A2. Traced the signal to a nearby LS245, then to another one, then it split three ways: A2 pin on the CPU, pin 92 on the chipset and some pin …
Re: Help with Octek Fox M 286 (broken chip)
Posted on 2022-10-25, 18:18
Having something brought to life after almost 5 years feels great, and that's one of the reasons I love this community 😀 Thanks for your reverse-engineering effort crackintosh.
Re: Super Socket 7 Lucky Star 5MMVP4 onboard VGA is VERY dim
Posted on 2022-10-23, 09:09
The image is there, so I guess there's no problem with H and Vsync. You mentioned inductors having high resistance of up to 2kohms when measuring across them, on resistance mode? They're definitely broken, normal DC resistance for those should be around 0.5ohm. I had a motherboard that had a bunch …
Re: Help with Octek Fox M 286 (broken chip)
Posted on 2022-10-23, 08:41
That's great, thank you guys! I'm away at the moment, but can't wait to burn the code into an ATF and revive my board! @REDLED, I'll have to read into this "Retro Chip Tester Professional", and also I find it interesting that your board lacks the third PAL (the one behind the ISA slots), and one of …
Re: Sad Voodoo 3
Posted on 2022-10-17, 23:01
Thank you all for your input. Not particularly proud of how this turned out, but I had to quickly check if the card is at least a bit alive so pentiumspeed 's method was out of the question (mainly because I'm lacking the high-temp epoxy and the experience :D ) 20221018_003801r.jpg At the initial …
Sad Voodoo 3
Posted on 2022-10-15, 21:57
Got this Voodoo 3 from today's flea market, but when I got home it turned out that the green spots that looked like corrosion were really corrosion :| They even reacted (bubbled) when I bathed the card in vinegar, so who knows, maybe the card was stored together with some leaky 286 boards or …
Re: Help with Octek Fox M 286 (broken chip)
Posted on 2022-10-14, 10:54
That's great, congrats! Does this mean you finally cracked the code inside 089-001 and you have a working board? If so, can you please share the JED file? Thank you.
Re: Help with Octek Fox M 286 (broken chip)
Posted on 2022-10-11, 21:23
Hi! If you manage to reverse-engineer the chip, please let me know. I haven't given up yet on repairing the board, but I just lack the skills to do it so I'm patiently waiting :) There might be differences between the ref.design and the Octek board regarding these PALs... There's three of them on …
Re: Missing SMD ASUS A7V400-MX -Help-
Posted on 2022-10-08, 20:47
Here are the boardviews for your board and the SE variant. The diode is a BAT54CW. Good luck fixing your hardware!
Re: Soltek SL-75FRN2-RL revival attempt
Posted on 2022-10-03, 22:21
Almost two years have passed, and during this time two new toys have found their way to my home lab: an oscilloscope and a digital microscope. From time to time I like to pull some board from the "dead" box and give it one more try, maybe using the above tools which I hadn't available when first …
Re: "Real time clock error" on a 286 Motherboard
Posted on 2022-10-03, 21:34
I think you need an oscilloscope for that, or if your multimeter can also measure frequency it could work. But 32.768kHz "clock crystals" are abundant and cheap, you could just replace it.
Re: "Real time clock error" on a 286 Motherboard
Posted on 2022-10-03, 11:32
Does the clock advance while you're in BIOS setup? If not, the crystal (I'm assuming Y2, 32.768kHz) might be bad. Had this happen at least once. [edited mistake, should be 32.768kHz or 32768Hz]
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