What I did was to turn the game on, and pop the pf up and basically gently jiggle the connector on those relays, and magically the lights popped back on. I knew then it was cold joints. And remember, I think there are a couple gi relays in these pins. So check all of them. The one I had an issue with was on the very bottom of the underside of the pf.. I think right side.
Can't hurt to jiggle things a bit and see if lights pop back on. ALSO, I'm sure you've reseated the GI connectors, but also try pushing in their wiring a bit into the connector. Sometimes the connector can be seated well, but the wiring isn't firmly pressed into the little groove on said connector. I don't know how many times in system 11 games this was the case.
Let me know if this makes sense. SOmetimes it's hard to explain in writing what to do.
ANOTHER THING: just because you reheated the joints, you could still have an issue with the female side of the connector, such as wiring not being pushed into the connector well enough. Jiggle things.