ok, so i have an update. It’s good news and bad, which is frustrating how the video keeps evolving.
I was able to bridge the pad for pin 2 on the ASC to restore the trace no problem. It worked great, stayed nice and flat, and buzzed cleanly back to A(5). This was the spot highlighted in green below. I decided to put the ASC back on and it went ok but I could not resolve a bridge between pins 27 and 28 on the corner. Then I realized the bridge was a copper pad from pin 28 (highlighted in red below). I was able to get it off without much trouble, so pad 28 is a goner. Maybe it wont matter in the long run because that pad does not have a trace that goes anywhere. The schematic says ATEST, so hopefully I got lucky.
Good idea on the socket. I guess I could have waited.
I booted the system despite the jailhouse video to test audio. No chime, abbreviated alerts sounds, and the simple beep still locks the computer—so no change. I pulled the board to double check my work, tried again and could not boot! I am now getting what looks like ones and zeros, but this is probably the simasimac pattern with the jailhouse overlay. See below:
I tried booting without RAM, swapped SIMMs, even pulled the ROM and the screen does not change. At this point, I stopped and took a break. It feels discouraging to learn so much about the board, to test so many connections, FIND a broken trace, only to take steps backward.
Returning to the bench I decided to clean up some of my previous work and inspect a few things. I removed, cleaned and resoldered C1, C4, C6, C12 and C13. I have already done continuity checks for these, but my soldering was a little messy and a few caps were not straight. Having done that it was getting late so I booted one last time to get the screenshot. Maybe it is my imagination, but I noticed after improving these capacitors that the video is not as shimmery as it has been. It seems more solid and does not wiggle as much.