Re: Imac G5 Video/Display problems.

Check the screen cable receptacle on the non outputing main board and check you have not damaged the tracks on the pcb. The GPU feeds the external video ouput and the internal lcd, there are however seperate buffer/drivers for the two devices the one to the lcd path may have failed. Aso check that the caps you have soldered in are not badly soldered and shorting the +ve to these buffer drivers. And of course do some voltage comparisons between the good board and the bad one. Its a luxury if you have a good board to compare with and even more so...