Success.....?

About two weeks ago, I ordered a 512K upgrade kit from Cloud 9. The kit arrived yesterday, got it all soldered up (yes, you have to solder the kit yourself) and plugged in (great product BTW). Was all jittery and excited, as with this one updated, I only have one CoCo3 with 128K - the re-pack.

Well, I turned the machine on and realized I forgot to plug in the VGA adapter - rats!!!. So I plug in the VGA adapter and turn the CoCo3 back on, all excited to see that nuclear green screen... and was greeted with a black and blue checkerboard pattern. WTF??? So I turned the power off. unseated and re-seated the upgrade board and tried again. Same damn thing.

After going over the work with a big ass magnifying glass, I discovered that when I removed the 6809 and installed the socket last week, I cut (really broke) a very small motherboard trace. Underneath the 'H' bar on the CPU socket of all places. No idea how I missed it when I was looking everything over before I soldered in the socket. Well, I got that fixed with a piece of voice coil wire (do you have ANY idea how difficult it can be to solder a piece of wire to a trace when the solder point is under some you REALLY don't want to have to remove..???), but, still had the same problem. 

After reseating the memory - again - and a few other checks, I was left with swapping out the 6309, which fixed it.

I doubt anything else was wrong; I ran the included memory test program for about 2000 loops, and played Donkey Kong (great CoCo3 stress tester) for about a half an hour and had no other issues.

Overall, the whole process was maybe an hour, including soldering the upgrade board. This was my first experience with a CoCo3 CPU going bad. Anytime I've had a PC CPU go, the computer failed to do... anything except turn the power LED on. Live and learn...