# Powermac G4 Tower Won't Start After Power Outage



## Triaker (Apr 10, 2006)

I need your help!  Last night I put my PowerMac G4 (Gigabit) tower in sleep mode, then put myself in sleep mode.  Early in the morning, we had a power outage.  When I went to start my computer to work on taxes, nothing happened.  No start up chime, no fan, nothing at all.  I tried unplugging and replugging back in.  Nothing happened.  Tried resetting the PMU, waited 10 minutes, pushed power button, and still nothing.  Tried pulling battery out to reset logic board, hit PMU button again, same results--absolutely nothing.  Pulled cover off of power switch and hit the little reset switch in there as well.  Nada.  Computer is plugged into a top-of-the line surge protector, and all other peripherals that were plugged in to same bar are working fine (external CD burner, printer, desk light, speakers).  Could it be the power module in the computer, and if so, how hard is it to replace?  I HAVE to get this computer running again asap to get my work done!  I leave this in your knowledgeable hands!


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## Triaker (Apr 10, 2006)

I also tried to use a different power cable to connect the computer to power.  Didn't help.  Now I'm stuck using my "ancient" Wallstreet G3 with system 8.5....  THanks for any advice.


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## barhar (Apr 10, 2006)

'Could it be the power module in the computer,'(?) - yes, it is possible.

'... and if so, how hard is it to replace?' - not very difficult. If it has been determined [see (1) through (4) links below] that the Power Supply is indeed in need of replacing - properly ground the PowerMac and yourself, remove a couple of screws, remove the upper tier drive(s) [hard disk drive(s) and 'Zip' drive, if installed], remove the ATA ribbon cable, remove the Power Supply screws and Power Supply, insert a replacement with its screws, replace the ATA ribbon cable and drives, add the screws, ... say a little prayer (or two) ...

(1) - 'Power Macintosh G3 (Blue and White) and Power Mac G4: Power Supply Voltage Test'.
(2) - 'Power Mac G4 (Digital Audio/Gigabit Ethernet): Power Supply Replacement Instructions'.
(3) - 'Power Supply Replacement' QuickTime movie.
(4) - Additional information: 'Power Mac G4 (Gigabit Ethernet): Customer-Installable Parts Instructions'.


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## Triaker (Apr 10, 2006)

Thanks for the hints.  I finally dragged the computer to a local guy who told me a new power supply would run about 175 bucks or so.  For 200 bucks he sold me an entire tower.  I swapped the drives and RAM out, and it seems to be working fine.  I also had to ditch the ATI Rage card, as it wouldn't power my Apple monitor, or my extra old monitor.  The older ATI card that came with the tower did fine for powering the old 20" monitor, but the logic board is different and won't power the newer Apple Monitor.  Oh well.  At least I can finish my taxes now!

Lesson learned:  always have your computer on a UPS power supply.  Even the fancy schmancy surge protector won't help you every time.  Apparently I wasn't the only one to suffer out here, as the guy I went to said he had 3 others with similar problems.  In older areas, without the newer wiring, substations, etc. being updated, you can experience actual polarity reversals when the power comes back on, which is what fried my power supply and graphics board.

Again, thanks for the help.  Hope this thread helps someone else in my predicament.


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## Satcomer (Apr 10, 2006)

Triaker said:
			
		

> Thanks for the hints.  I finally dragged the computer to a local guy who told me a new power supply would run about 175 bucks or so.  For 200 bucks he sold me an entire tower.  I swapped the drives and RAM out, and it seems to be working fine.  I also had to ditch the ATI Rage card, as it wouldn't power my Apple monitor, or my extra old monitor.  The older ATI card that came with the tower did fine for powering the old 20" monitor, but the logic board is different and won't power the newer Apple Monitor.  Oh well.  At least I can finish my taxes now!
> 
> Lesson learned:  always have your computer on a UPS power supply.  Even the fancy schmancy surge protector won't help you every time.  Apparently I wasn't the only one to suffer out here, as the guy I went to said he had 3 others with similar problems.  In older areas, without the newer wiring, substations, etc. being updated, you can experience actual polarity reversals when the power comes back on, which is what fried my power supply and graphics board.
> 
> Again, thanks for the help.  Hope this thread helps someone else in my predicament.



If you homeowner's or renters insurance it may help in the cost.


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## northmendo.com (Apr 10, 2006)

Dude Your Other Case Is Probably Fine This Happend To My Emac And I Unpluged It For 24 Hrs And It Now Works Fine.


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## RGM (Apr 12, 2006)

Triaker said:
			
		

> Thanks for the hints.  I finally dragged the computer to a local guy who told me a new power supply would run about 175 bucks or so.  For 200 bucks he sold me an entire tower.  I swapped the drives and RAM out, and it seems to be working fine.  I also had to ditch the ATI Rage card, as it wouldn't power my Apple monitor, or my extra old monitor.  The older ATI card that came with the tower did fine for powering the old 20" monitor, but the logic board is different and won't power the newer Apple Monitor.  Oh well.  At least I can finish my taxes now!



I just posted a reply to someone else and mentioned power outages. Thot I'd put it here, too. I've been an elect. tech for over 40 years, and have a minor in electronic design on masters deg. The AC power is, by definition, constantly reversing polarity. The big problem in a power outage is the reconnection transient voltage spike that occurs when the crews reconnect lines or snap-switches on poles. This voltage spike can be (usually is) enormous. In the ball-park of 1000 to 1500 volts. Not only can that spike wipe out delicate electronic equipment, computers, radios, stereos, HDTVs, it can destroy house air conditioner compressors if they are connected by their start relay, and refrigerators.

We have lived in communities which have lots and lots of power outages. I have seen the damage and experienced it at my own location. I never leave my computer connected to the 120 supply when I am not using it for more than 5 or 6 hours. In the case of power outage, I disconnect refrigerator and microwave, and shut down the central airconditioner. People across the street had to replace their AC unit last summer due to an outage and turn on transient. I shut mine down the minute the power went out.

Power line turn on frequently involves not one turn-on attempt by the power crews, but several, and each one has that voltage spike. I have gotten to where I wait for an hour before I believe that there won't be another off-on episode, and then reconnect everything. Remember, most of your electronic equipment is on in stand-by mode whether it is on or not. If it is connected to the socket, it is on. I have learned the hard way, disconnect when not in use. The UPS may save the day, depending on its design. If you are going to leave the computer connected and potentially on constantly, definitely use more than just a surge protector strip


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## mersyone (Jan 13, 2007)

Wow!  Great advice RGM!  I will definitely reconsider my power-plugging habits as my Power Mac G4 has just literally, ...gone up in "smoke".


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