Portable blank display row after recap

[Aeroform]

Hello! I just recapped a Macintosh Portable. It boots and seems to work fine, however, it has a row about 20-30 pixels high at the top of the screen that doesn’t work (see images). I’ve tried several displays, so it must be something on the mainboard that causes it.

Any tips for likely culprits / troubleshooting? I don’t have much except a multi meter to beep out traces etc. Can a wrongly installed capacitor cause this issue?

Is there a simple guide to points where I can check continuity for the caps I installed? I checked for shorts and that they were all connected to ground OK, but the positive sides were harder to check on most of the caps.

Thank you!

 

[Aeroform]

Started poking around the contrast curcuit and seem to have found a broken trace going to Q12. It’s on the other side of the board so will hunt around some more to hopefully not have to run a super long bodge wire

 

[Aeroform]

Spoke too soon. Everything in the contrast curcuit checks out OK. The hunt continues.