help with pram reset & other no video fixes?

[akb427]

All the directions I find for "reset the PRAM" are not precise on what gets held down when.

Should I be holding command-option-p-r while I press the triangle key that starts the machine, release the triangle key but keep holding the other 4?

Or is it press power key and after releasing it, press the other 4?

And is using the power button exactly the same as using the triangle key on the keyboard?

I have a power mac 8500. It booted ok last week, and would not do so this week; it powers on and chimes, but no video. 

A few times it made the car crash sound. 

I have reseated the CPU and RAM, given it a new PRAM battery, hit the CUDA switch. It will power up and chime, but no video. 

Suggestions? Thanks much for any clues... 

 

[Byrd]

As soon as you power up the machine, quickly move to the command + option + P + R keys held down continuously until you hear a chime, and keep these keys held down until you hear the chime two more times.  It can take a minute or two to perform this task.

Re: PPC 8500; strip it down to the basics - one known good DRAM module, two good VRAM modules, install a fresh PRAM battery, remove all PCI cards.

JB

 

[akb427]

Thanks very much!

I've stripped out most RAM modules, still no joy, I will now try swapping a few of them around. 

Does the machine need a cache chip in order to boot?

Can I use the CPU board from a 7500/100 (630-1219-A) ?