ok so i have been working on this computer this guy brought into the shop for an hour or two and I cant get it to come on. He said he got a bsod and it cut off and would not come back on. well i have replaced every piece in the computer and nothing will come up on the screen. The psu comes on and all the fans are working, I can hear the HDD spin at first too. I have replaced the ram, the cpu, the psu, taken out all unnecessary hardware. differenct HDD, different mobo. tried a pci GPU(it has onboard). Im really stumped on this one. even tried different case, and monitor. always does the same thing. any help would be greatly appreciated!