Power Mac G5 LCD wont start

Hi, at work we have a Power Mac G5 with 2 large 24" LCD's connected. This is video editing machine. However about a year after we bought this system when we turn it on, one of the LCD's refuses to turn on with the other one. It does turn on about 50% of the time by itself after its booted into the desktop, then we have the 2 LCD's up and running correctly but its a sit there and wait game.

The power box on the LCD that isn't working is stone cold.

We do have alot of devices connected so we were wondering if its a power issue but all of the external devices all have their own power sources:

6 x External HD's
1 x DV Deck

Any help appreciated.

Have you tried connecting the 'dead' LCD to another computer and see if it will come to life? Or changed the displays DVI connections about?

I used to have similar issues on my (sic) main Windows desktop computer, problem was traced down to a fauly DVI output on the video card......the other worked flawlessly, while one was a dud, replacing the card fixed it but good. Just an idea.

Hi, thanks for your replies but still can't figure out what's going on.

We tried switching over the DVI connections and both LCD's are working fine but not together. One of the white power boxes which is connected to the LCD which always either fails, flickers non stop or is slightly dim is never quite as hot as the other power box which always powers the LCD which works fine.

After restarting the machine about 50 times and swapping cables around in all combinations both monitors came onto together but one is ever so slightly dimmer than the other. This is the routine we have to go through before we can get both monitors up and running correctly. Otherwise usually every morning when we boot up one comes on and the other one comes on after about 5 mins (if it feels like it).

I was reading somewhere about PMU's could this be the problem or could we have a power box failure?

What AGP graphics display card are you using, and take it also have a second or PCI card set up for the second monitor?

We have an Nvidia 6600 pci card. Couldn't find a way to manually update that particular driver apart from doing an entire OS system update. We are reluctant to do this because last time it knocked out our RAID SCSI drive and are also worried about if Final Cut pro will still be compatible.