Amiga 600 analysis
It's a little dead, Jim
Today I've tested my recapped Amiga 600 to figure out why there's a color distortion.
I'm using the Kickstart Rom replacement Diagrom 1.2 by John "Chucky" Hertell diagrom.com to do some in-depth analysis
I originally bought an v1.1 A500/A600/A2000 Rom back in January, but the chip turned out to be broken. Many thanks to homer79 (ebay.us/e1S2jr) for replacing the dead chip for me for free. Excellent support. Much appreciated. Excellent seller.
The hardware diagnosis was partially successful: No issues with the CIA, IRQs or any of the memory tests.
However:
- L/R Audio channels aren't stable
- Mouse didn't respond and Diagrom reported stuck buttons (JoyR + MouseR) upon the 2nd reboot
- 5-6 Reboot attempts were required to get a working mouse
- Super weird color mess
Reboot issues: 3 power cycles were often needed to get past these Guru Meditation chains.
Color mess: The boot screed is supposed to be white - but there's a gradient. I've got no idea how this even gets triggered.
Kickstart screen + Workbench. Colors are all over the place and there's some intense bleeding. My original suspicion was that the green video line was broken, but this is something much more complex.
The graphics test in Diagrom are also quite messy:
Audio issues: The left audio channel is a lot louder than the right one. This normally points to a bad capacitor, but I've tripple checked the caps. When inspecting the plug connectors I noticed huge corrosion mess that I didn't spot earlier. (I wasn't able to make pictures)
Wiggling the connector restores audio. So I guess this is fixable be re-soldering the plugs.
But the overall machine is super unstable. Agnus (U2) chip gets super hot, impossible to touch with bare fingers. Poking the 8520 VIA (U8) chip reboots the machine.
This is beyond anything I can repair. I will however continue to investigate why the RJOY1 and RJOY2 is line is high all the time, causing the stuck right mouse button.
I'm not 100% certain that my recapping killed it. I wasn't able to fully test the machine before because I had no RGB video cable and then one of the caps fell off on it's own.
But, I think it's fair to assume that my soldering action killed the board or one/some of chips. ("Gameover?" track by Tim Bartlett)
(YouTube Direktlink)