Power Mac G5 Blank screen and no chime on start up
I have a Power Mac G5 (June 2004). Recently when turning on the plug switch (at the wall) there was a power surge to the Mac which blew the internal power supply. I bought a reconditioned PSU and replaced the blown one (following online instructions). When I turned it on again, it booted up, but without the start up chime and a blank monitor screen. The monitor power light is on, but nothing appears on screen (black). Eventually the fans go crazy and only stop if I turn the Mac off. I can't boot up in safe mode as there is no chime and have tried command shift P R to no avail. After much searching I'm lost as to what to do next.
Anybody have any ideas?
PowerMac