MUST MORE EXTENSIVE VERSION OF THIS LIST ON THE WAY!
Most of the issues we’ve come across with the N64 are related to dead solder joints, corrossion, and just plain dirty.
Heres a list of the most common problems we come across on the N64
Dirty cartridge slot, remove dirty and grime via a needle
Something on the board will need a reflow, av port, power port, controller ports, ect. dead solder joints riddle the N64
cartridge slot needs to be pulled off, cleaned, and put back