Well, I recently acquired a PowerMac G4 (FW 800), and a Formac 17" ADC display for my brother. At my apartment, everything seemed fine. It was booted up at my place for maybe 2 hours without a hitch. I brought it down to his place yesterday, set everything up, and started it up. Everything was fine for about 3.5-4 hours, and then the computer just shut off. After some fiddling, I discovered then unplugging the display allowed the computer to power up, but when I plugged the display back into the computer it immediately shut down. When the display is plugged into the computer you can hear a faint clicking coming from the PSU.
This leads me to believe that because the display is drawing power from the computer instead of the mains that it is causing a drain on the power supply. I guess my question is why is this happening, and why was it working flawlessly for hours before this happened? I don't currently have another ADC display to test, nor will I will be able to get over there with a DVI display (the computer has no VGA port) anytime soon. I've considered ordering the Apple DVI to ADC adapter to get the display independantly powered, but I would appreciate some advice before I throw another hundred bucks on an aging machine. Thanks!
Sounds like a bit of a waste, since it sounds to me as if the ADC display in question is broken. Apparently it's not alone:
http://www.macmod.com/forum/showthread.php?t=1639
If you have a VGA monitor lying around you can get an ADC->VGA dongle for about twenty bucks:
http://www.mac-pro.com/s.nl/sc.2/category.128/it.A/id.230/.f
--Peace
maybe the aging machine has na aging power supply that has become unstable? perhaps a new power supply for your machine?
I figure the question is - how much would it cost to just replace the Formac display? The cost of the adapter, plus a few more bucks will give you a brand new display. And how many hours are on that Formac? If lots, then it may not last much longer.
Of course, I suppose one could make their own adapter. Did anyone complete a ADC to DVI+power hack? Seems they did but I can't recall details.
OTOH, it sounds like the Mac's power supply is fading, or at least the part that supplies 28V. Still, in an case, I think it's better to get that display off the Mac's PS.
I've always wondered about the efficacy of using the Mac to supply power to the display, seems a bit bassackward to me.
dan k
I was given one of those Formac 17" LCDs, but I was also given an AC adapter that originally came with the monitor. It's pretty much like the Apple adapter -- DVI and USB connection to computer, AC power in, and socket for ADC monitor to connect to. Maybe if you get lucky you can find one on eBay.
Unless you *know* the monitor works on another computer there's no reason to blame the power supply in the computer. The PS in the ADC Macs can handle driving a CRT display, after all. (The original 17" Studio Display) Assuming the Formac is an LCD monitor it's going to draw *way* under the rated capacity of the supply.
If there's another ADC-equipped Mac around to try the monitor on I'd do that before spending a dime on it.
--Peace
Thanks for all of the advice. I am going to ponder my options and see what is most cost effective. I will let you all know how it works out. Thanks again!
After much hassle and experimentation, the Formac is officially toast. I was *really* hoping it was something else, but thems the breaks. I've replaced the display with another DVI flat panel, and the old Power Mac is chugging a long like a champ. Thanks again everyone!