PowerMac G4 Not booting up, loud fans

[tupacalypse]

I recently found my old G4 in my basement and it was working for a couple of days and last night it froze and now when I try to boot it up the power light comes on for a seconds then the fans get to 100% and nothing shows up on the screen. Also when I unplug the Mac display that uses the ADC connector the computer will shut down, also it doesn't not boot with a dvi monitor.

I've tried a few things like re seat the ram and GPU, removed the battery, but nothing is working.

Has anyone else run into this?

 

[COLGeek]

You likely need to run the old diagnostics program (good luck finding if you don't have already) to "reset" the system. I recall this with a G4 I had several years ago doing something very similar. You had to boot the diagnostics from a CD/DVD.

Good luck.