Today I realised that I'm never going to find a spare Tseng ET4000/W32P chip available and I have to use what I have. I bought a broken Genoa Phantom 32i 8900VL card, probably from someone on here 😀
It started out looking like this:
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Now it looks like this:
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It's had a bad time. This is my second attempt, the first was a few months ago with the dremel and using enamel wire I rebuilt the missing chip legs. It didn't work and just made some noise on the display when I tested it so it went back in the box.
A few months later I thought I had sourced an undamaged chip but no, I had mis-remembered and bought a TC6167HF. This is a TC6169HF - not compatible at all and the pin counts are very different, but I guess this means I can test them both now heh. The TC6167HF is attached to a compaq 486 motherboard that I bought as scrap and it's rusty on the ports area, but works just fine after reinstalling one missing jumper and straightening 2 chip legs.
So today I had another go at installing this chip, pulled it off the card again and removed all my original leg repair wires. Took it slower this time and used the microscope to re-align all the chip legs as they were all over the place last time. This time around instead of using enamel wire, I've used single strands of bare copper wire from a mains cable. Much easier to work with and this time the card booted up with no graphical glitches, that is awesome.
It could only see 512KB of its 1MB of RAM though, briefly checked some of the important data pins and thought to use the thermal cam to check for a short or...
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Thermal cam ftw 😁 The SOJ ram in the lower right, its VCC pin was no longer connected to the board and was probably bashed off the same time this ET4000/W32P chip originally got dislodged, soldered that back on and now it can see not 1, but 2MB of RAM (borrowed). I'm so glad, I wasn't in the mood to do 2 complex fixes today.
Anyone know of good part codes for DIP20 256Kx4 5v memory with low latency? Looks like the DIP version of the original is the way to go with V53c104HP-45 chips