iMac DV won't startup

[zeb]

I was trying to upgrade my fathers old iMac DV to Panther from 9.2.1... the install CD told me that I needed to update the firmware. The only option was to click "Close", after which the screen went blue with the rotating thingy near the bottom. After at least 5 minutes of this I figured that it was hanging and held down the power button on the front to turn the computer off (probably really dumb)... Now I can't turn it on. What happens is that when I press the power button, it chimes and the green light turns on, but after 10-15 seconds, it turns off (though I can hear the screen turn on, there is never any picture). After it turns off, if I try to turn it back on, there is no startup chime, just the green light. I need to unplug the power cord and plug it back in in order to get a startup chime. In twelve years of trouble shooting Macs, I have never seen this sort of problem.

I can't startup from the Panther CD or the computers original software install CD.

Any ideas? What was the Panther install CD doing after I clicked "Close" (the blue screen with the rotating thingy)? I assumed it was getting ready to restart so I could download and update the firmware in OS9... It couldn't have been updating the firmware on it's own without confirming first... right?

[trevor]

I don't think you've done any permanent damage, since you weren't actually updating the firmware at the time of the force quit. You need to zap the PRAM and reset Open Firmware: directions here. If those steps don't work, then reset the CUDA switch.

Once you get your computer back, make sure you do update the firmware.

Trevor

[zeb]

I've tried all of those steps. After holding down the keys while trying to boot up seems to be ineffective, it just turns off after 10 or so seconds without chiming again. I tried looking for the CUDA reset, which I seem to remember being labeled in all other machines, but the only switch I could see though the little portal in the bottom of the iMac wasn't labeled. I pressed it anyway (15 sec). Is the CUDA reset button buried elsewhere in the iMac?

I also tried holding the programmers button while booting up... I got the long tone (as opposed to the chime) but nothing happened after that.

Anyone know any other tricks? Is there an actual CUDA switch that I missed?

[DeltaMac]

Test or just replace the PMU battery, which you can find by looking through the bottom access door toward the rear of the computer. It will be green or purple, in a small holder, about the size of a AA battery, but half the length. Remove the power cord, pull out that battery, let the system set for a few minutes. Battery should be between 3.3 and 3.7 volts DC. I would suggest replacing anyway. After inserting the battery, press the PMU reset button (that's near the end of the RAM slots, the only button, probably what you already tried) once only for 1/2 second. DO NOT press a second time just to make sure. Let system sit for 10 seconds or so. Then plug in power cord and keyboard/mouse. Press the power button. Hold Opt-Apple-P-R until the startup tone goes at least twice. If your system powers back off almost immediately again, then you have other hardware problems and should take it somewhere for service. Your power supply is probably bad (it's part of the video board, Apple calls it a PAV board) replacing that board will probably set you back a couple of hundred dollars. If the system does power up, then you should be OK.

[mssdvm]

This is a known problem in iMac 's when you try to upgrade to X without upgrading firmware first ( here are some links :
http://pub134.ezboard.com/fmacnighto...icID=218.topic

http://www.macosxhints.com/article.p...uery=dead+imac).
It is not usually a power supply or video board problem. I have seen it many times when doing tech support. Replacing the PRAM battery (get one cheap at Radio Shack) and resetting the CUDA chip can help in some cases but not all. The last two I resurrected I had to remove all RAM, reset the CUDA after updating the battery and then let it sit unplugged for a number of hours, reinstall the RAM and restart with fingers crossed! Hope you get it to start!

[zeb]

Well, I'm not sure exactly what it was that I tried, but I'm pretty sure it was the RAM. I replaced the battery and reset the CUDA again, but I still had no results. Then I took out both RAM chips and when I pressed the bower button, it immediately gave me the tone and stayed on without doing anything. So I tried putting one RAM chip in which didn't work, and then I tried just the other one in the other slot and was at this point able to reset the PRAM and startup.

The only problem now is that the monitor is screwy... It looks like the blue channel is offset. Is there any reason why I should be getting these results? I'm aware of how to fine tune this problem on a basic monitor (with the hardware dials inside the case), but is there possibly a software fix for it?

[zeb]

hmmm... oddly, when I put the other RAM chip back in, I am able to startup completely, but with no video at all..... I tried resetting the PRAM again, which flashed a gray screen in-between one of the chimes, but still no video. (The gray screen looked like the green channel was out of sync.)

Using only the bad RAM chip resulted in the same initial problem of not being able to startup. Using both chips results in no video. And using only the good (or should I say "not as bad") chip results in the funky blue video.

I can see the desktop and everything else, it's just appears to be an issue of the guns not lining up.

Is it possible that this other "good" RAM is causing this video problem? maybe I'll try to upgrade the firmware next and see if that does anything...

Thanks for your help so far.

[zeb]

I am in the process of updating the firmware...

I downloaded the updater, opened it and clicked shut down. I followed the instructions... I held down the programmers key during startup heard the long tone, and then the chime... after a while I heard three consecutive tones (not chimes) and now the power button is flashing... it gives a solid green for 5 seconds, then three quick oranges and then green again for 5 seconds. I'm not sure what's going on because I don't have any video.

Any Ideas? Should I shut it down and try again? I'm reluctant to interrupt the power again since that's what caused this problem in the beginning.

[zeb]

okay, I just got fed up and held down the power button, after which it started up great and informed me that the firmware was properly updated. The screen is back to normal. Now let's see if the OSX installer works.

Thanks!

[vaughncorden]

I'm having the same problem as this poster, which is I made the mistake of starting to install OS X on a slot loading imac without first updating the firmware. I got the "Close" button from the OS X installer and then the perpetual spinning wheel. I, too, forced a shutdown and now the machine won't startup anymore.

I get a startup chime, a flashing caps lock key, and then an immediate shutdown. I've tried all the suggestions in this thread (new battery, pressing the CUDA switch, removing RAM, trying other known good RAM, letting it sit unplugged with no battery or RAM for hours) all to no effect. The machine is obviously still functioning because I get a nice startup chime, but I just have figured out the magic formula yet.

BTW, I MAY have pushed the CUDA switch twice within a few seconds in my many attempts to trouble shoot this. Is that a fatal mistake? What are the implications?

If anyone has any suggestions, I'd sure appreciate it! This is a friend's Mac that I said "No problem, I can upgrade it for you!" I'd hate to have to give them back a non-functioning machine.

MSSDVM, you seem to have come across this before. Feel free to contact me directly if you have any suggestions.

Thanks so much everyone!

[spkrman]

If your imac shuts down after 5-10 seconds and you cannot update your firmware, a solution that worked for me can be found here: http://frderi.spymac.net/imacresurrected
NOTE: this is not for the technically challenged.
It saved my niece's Imac from an untimely death. Ironically, this is the only machine that has ever given me trouble installing OS X, and all the other machines weren't even supported.