Troubleshooting N64 in GB Player mod.

I've been trying to replicate Hailrazers awesome N64 in GB player mod lately, and the only thing I had left last night was adding heat sinks to the N64 and reassembling it.
However, when I replaced the SD card in the Everdrive 64 this morning, the N64 stopped booting.
The LED still lights up and I'm getting 5/12v out of the 7805.
The cartridge is at least getting some power, there is a faint green light from the LED, but the regular three blinks from it when the N64 boots aren't happening, and there is no audio/video being displayed, although there is power in the RCA ports.

I can't think of where to go from here, I checked all the wires for the relocated cartridge slot, checked and resoldered the power cables 100 times and so on. Could it be something wrong with the jumper pack slot or something?
I've tested both the jumper pack and the Everdrive in another N64, and they still work fine.

 

Im sure many people can help here, but you may want o check out the bacteria forums. Hailrazer is over there frequently and since it specializes in console modding, you might get quicker responses. Anyway, good luck getting it sorted.

 

I would, but it seems like the bacteria forums have been down for some time (if http://www.made-by-bacteria.com/forum is the correct URL). :/