I've been wanting to repair a pair of DTK 286 boards I've had here for a while. Finally got stuck into it today.
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Both boards had bad battery acid corrosion.
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Both boards were missing the BIOS ROMs but luckily I could find the DTK BIOS on the net so I could write a couple of 27128s.
One board was doing nothing when powered on, the other would post OK but give a keyboard error, so I concentrated on that one.
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With the keyboard connector right next to the battery, I was fairly certain the problem would be a broken trace from the corrosion, but all the keyboard connector pins were connected up correctly, so had to dig deeper. Using the logic probe I found a missing input on the nearby 7407, which was indeed caused by a broken trace, the corresponding output goes to the keyboard data pin. A bit more searching around the keyboard clock signal discovered another broken trace somewhere between a 7404 way up at the top of the board and pin 37 of the 8042 which for some reason ran indirectly via the area of the corrosion.
Bridged the broken traces with hookup wire and gave it a test. With the keyboard working now I can get into the bios an set everything up and get it running, once I put a new battery back on.
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