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quatermass

macrumors 6502
Original poster
Sep 19, 2009
334
532
Hi all,

Im at my wits end, and the end of my knowledge so that’s why I’m here.
Last night, at about 4:30am, we had a power failure, or brownout or spike or something, because my UPS started its incessant alarm screeching. Got up to see what was up, the Mac and monitor were off - I guess the battery had run out or it shut down, so I turned the UPS off and went back to bed. This kind of thing has happened before - the power can be a bit flakey out here, but it’s never affected the Mac. Come the morning, I turn everything back on in the proper order, made the usual noises, fans started, CD drives chugged, but nothing on the monitor. “No HDMI signal from your device’“.
Ive disconnected everything, restarted countless times with just about every key combination I can think of, but nothing works. I took out the SSD, which is the boot disk, and replaced the original HDD which I know was working, but that hasn’t worked. I swapped the graphics card for the original GT120, tried with a different monitor, and that hasn’t worked either.
The machine is alive - the fans come on, CD drives, the RAM check lights on the risers come on, then go off, like normal, so I doubt that it’s a RAM or power supply issue, but I’ve come to the end of my knowledge. I’ve skimmed through the various threads here and tried many of the ideas that I thought might be relevant, but to no avail.
Fellow cMP users... is there something I’ve missed? Something obvious I haven’t thought of? Some simple hardware or software issue? At this stage I’ll try anything!
The machine is as shown in my Sig below... my thanks in advance for just reading this! My only option at this stage is a 2nd hand Mini, just to get the work done... I really don’t want to lose my client!
 
Hi all,

Im at my wits end, and the end of my knowledge so that’s why I’m here.
Last night, at about 4:30am, we had a power failure, or brownout or spike or something, because my UPS started its incessant alarm screeching. Got up to see what was up, the Mac and monitor were off - I guess the battery had run out or it shut down, so I turned the UPS off and went back to bed. This kind of thing has happened before - the power can be a bit flakey out here, but it’s never affected the Mac. Come the morning, I turn everything back on in the proper order, made the usual noises, fans started, CD drives chugged, but nothing on the monitor. “No HDMI signal from your device’“.
Ive disconnected everything, restarted countless times with just about every key combination I can think of, but nothing works. I took out the SSD, which is the boot disk, and replaced the original HDD which I know was working, but that hasn’t worked. I swapped the graphics card for the original GT120, tried with a different monitor, and that hasn’t worked either.
The machine is alive - the fans come on, CD drives, the RAM check lights on the risers come on, then go off, like normal, so I doubt that it’s a RAM or power supply issue, but I’ve come to the end of my knowledge. I’ve skimmed through the various threads here and tried many of the ideas that I thought might be relevant, but to no avail.
Fellow cMP users... is there something I’ve missed? Something obvious I haven’t thought of? Some simple hardware or software issue? At this stage I’ll try anything!
The machine is as shown in my Sig below... my thanks in advance for just reading this! My only option at this stage is a 2nd hand Mini, just to get the work done... I really don’t want to lose my client!

Well, it sounds like your monitor is working well enough to display a message, so you can probably assume that component is operational. Your GT120 card wasn't installed when "the incident" occurred, so presumably that component is good. The Mac Pro has been unplugged for a while, so the SMC should have been reset; if not, unplug the box for 30 seconds. I would leave the GT120 installed, unplug all external cables and remove any other PCI-E cards that you may have installed, as well as all hard drives; you want to get pared down to the absolute minimum that should put something on the screen. When you start it up like that you should at least get the "question mark hard disk" icon displayed after a while. Also, you didn't mention: does it make the startup chime/chord sound?

If that doesn't work you might try moving the GT120 over one slot to the other x16 slot, just to see if that makes it put an image on-onscreen.

If, after all that, you can't get the icon on-screen, well, then your backplane is probably damaged. I personally have seen this kind of damage happen when a UPS runs out of battery; I don't suppose you have a CyberPower UPS, do you?
 
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