[Sammy_J]

I have a DP 1.8 Ghz G5, 1.5 GB of RAM, 2 HD (160 & 250) and everything else is stock. I use a Viewsonic CRT using the DVI - VGA adapter.
The problem is that every once in a while, the machine does not boot up. The status light is on on the tower but the screen is blank. The monitor doesn't even get a signal cuz it'll show the "No SIGNAL" message and then click into stand by mode. When this happens, I have to manually power off (by pressing and holding the power button) then unplug the machine, wait a little bit and then plug back in. In most cases, this fixes the problem and everything works as normal.
Any ideas as to what might be causing this? Could it be a RAM problem? The G5 came with a stock 512MB and I added 2 512MB cards after the fact. I didn't have a say in the origin of those RAM cards but from what I can see, the company than supplied the RAM shows that it is compatible with G5s. Unfortunately, the name of the company eludes me... The machine belons to U of Chicago and they have pre-determined vendors that I have to use...
So any ideas why my machine has this problem?
Thanks,
Sam

[MacCheetah3]

Hi
It sounds like you're accomplishing this without even knowing it.
Apple Knowledge Base Article #300341 - How to reset the SMU on a Power Mac G5 (Late 2004)

As the article above also points out, I'd also try resetting the PRAM and NVRAM.

Apple Knowledge Base Article #2238 - Macintosh: How to Reset PRAM and NVRAM