Dead AV Modded Jr?

[yell0w_lantern]

Over a year ago I installed a Longhorn AV mod on my Atari Jr. It worked fine for a while (several months?) but then I had to start tapping it when I started it up so that I would get picture. I hooked it up after several more months and now I get absolutely nothing. The screen stays black when I turn it on although the power LED turns on; no sound. I get the same black screen with or without a cartridge. I even tried cleaning a couple of carts. I tried the Harmony cart too. I even considered it might just be a video problem so I pressed reset half expecting to hear a game start but no such luck.

 

I opened up the console and checked the ground which turned out to be a little loose so I resoldered it but that did nothing. I tug tested the wires and examined the traces on LE's board but everything looked okay. No loose components either.

 

I'm wondering if a chip died or something. Anyone seen this before?