Amiga 2000 Green to Gray to just Gray failure

[raoulduke]

Hey, I got a 500 and 2000 yesterday.  The 500 PSU is ... it's not dead but let's just put a pin in what's wrong with it.  The 2000 worked fine but it had bad battery corrosion so I cut the battery out, did what I could, and washed the board.

I was trying to replace the HD and over time I started to get more and more red-on-black software/system failure codes.  Eventually it only started to a green screen.  I did a really, really bad job of deseating Fat Lady and as a result pushed some of the pins in the socket away from contact (does that language make sense?).  I subsequently tried to pull them outward and I think I have, but I'd like someone to chime in on whether maybe I'm disrupting the socket pins' contacts to the board.  Oh... and Fat Lady was also a bit corroded so with that hard deseating one (and then eventually another) pin fell off - may have just been the corrosion; I'm not sure.

So I replaced it with the Fat Agnus from the 500 to no effect.  After a bit of reading I reseated the 8520PL chip and now the green screen is gone.  The green screen problem was a 10x repetition of green to weird interlaced gray lines (10 cycles of that switch, i.e. green-gray-green-gray etc.).

After a minor blip it's still on that.  I'm trying a deeper clean with everything desocketed.  There are also two wire-stubs (not connected to anything and snipped close to the pins) on the Kicstart 2.04 ROM and I have a Rev. 4.4 mobo.

The ROM question is pure curiosity but does anyone have thoughts on how to proceed with the more catastrophic issues?

[I can solder and despite my stupidity here I have resurrected a number of boards, though these are my first Amigas.]

[raoulduke]

Yes but in a good way.  I don't think I described the 'damage' I did that well.  I swapped all the chips for the A500 (and I left them that way out of laziness) - all except the one in the upper left 31420 something? and the 68k, which I'm pretty sure was dead in the 500.

Symptoms were basically the same and the only difference came when I'd reseat Agnus.  Eventually I just opted not to seat it properly.  It's half seated pushed into the top.  Like it won't fall out if turned over but it's essentially resting on the tops of the pins - so I know it's making full contact.  And it works beautifully now.  And of course you were right - as I suspected - it was Agnus.  And it may have also been my doing.  Maybe the system errors I was getting before were just flukes.  Or maybe some or one of my chips died/is dying.

Any thoughts on the Kickstart ROM wires?  Actually, might he have just upgraded - like bought someone's ROM later on - and that person had modded it for a Rev. 3 or 5 board and he undid it for the Rev. 4.4?

(If these were an A2000 mobo I'd fix them, but I can't figure out the rotation...)

[raoulduke]

This is what I mean by the chip; again sorry about the picture...

The first shows the 'damage' to the pins and the second shows my solution.  The 'damaged pins' in the socket are just below and to the right of the "23" on Agnus.