I was fortunate enough to get asked to take a look at a Quantum board. Had not worked on one, but was willing to give it a shot!

First I had to build up my bench harness which connects into my Atari Bench Power Test Rig.

I start with just the power connections and verify and recheck them before connecting to a PCB. I can usually start working on the board with just power to start. Once I determine I need controls I wire the small 15 pin Molex to match the appropriate bench controller. Finally once a vector game is running on the scope – I wire up the large 15pin connector for my bench 6100.

Board #1 – Quantum

Reported with Graphics issues. Powering it on, board was watchdogging. I had already verified all the ROMs and tested all the RAM (off board), cleaned legs, DeoxIT, etc.

Quantum uses a 68000 processor, so no ability to plug in with the FPGA Catbox and verify bus operations. Spent some time checking the data and address busses, but they all seamed like they were working. It appeared the address decoder PROM@1C was not signaling on pin 12. I burned a replacement GAL chip, but no joy. I was still learning the board and a little research showed that even the Pokey’s could prevent booting.. Pulled the originals and replaced them.. board booted! Put them both back, board booted?!

Dirty sockets? I’m going to replace them.

I haven’t done all the testing yet, It doesn’t seem to be saving high scores.

Board works!