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hewler
Jul 4, 2010, 12:34 PM
Yesterday I pulled out the power cable for my g4 by mistake and it shut down. After that, I can not start my computer. Nothing happens when I press the power button. No sound comes from the computer and it does not smell burnt. What can I do? Please help me!



DewGuy1999
Jul 4, 2010, 01:10 PM
Are you sure you got the power cable plug put completely back in?

hewler
Jul 4, 2010, 01:17 PM
Yes I am sure. I have tried many times.

Damnations!
Jul 4, 2010, 01:17 PM
Seeing as it doesn't smell burnt, I think we can rule out fire, serious overheating, and burning.
Are you sure you're pressing the on button? I remember when I got my first Mac. I couldn't find the power button for the life in me. Turns out I was holding it upside down.

hewler
Jul 4, 2010, 01:31 PM
Thanx a lot for your answer. I have used this computer for a few years now. There is no problem with the power button. Exactly like before.

Hrududu
Jul 4, 2010, 02:11 PM
What kind of Mac is it? Powermac, Powerbook, iBook, iMac?

hewler
Jul 4, 2010, 02:41 PM
It is Power Mac G4 2 x 1 GHz with OSX 10.5.

mrchinchilla
Jul 4, 2010, 03:42 PM
Have you tried looking inside the unit for any signs of physical damage to the PSU?
Do you have a spare AC cable? Perhaps a wire broke when it was pulled out.
Or perhaps the fuse has blown in your plug socket?

DewGuy1999
Jul 4, 2010, 06:03 PM
Give the PMU reset a try:

How to Reset Mac PMU: Simple Steps for Resetting the PRAM, NVRAM and PMU (http://www.macusersguide.com/2009/05/resetting-pram-nvram-pmu/)

hewler
Jul 4, 2010, 06:23 PM
mrchinchilla: I can't find anything broken in the computer. I have tried with different cabels. Same result.

DewGuy1999: I have tried the instructions in the given link. But the problem is there is no reaction at all when I press the power button. Nothing happens. I am confused.

DewGuy1999
Jul 4, 2010, 06:41 PM
mrchinchilla: I can't find anything broken in the computer. I have tried with different cabels. Same result.

DewGuy1999: I have tried the instructions in the given link. But the problem is there is no reaction at all when I press the power button. Nothing happens. I am confused.

The only other thing that I can think of beside the obvious dead power supply is that maybe it needs a new PRAM battery. I can't explain how or why this would of coincided with the pulling of the plug, but sometimes things are just a coincidence.

I have a Bondi Blue G3 iMac that behaved the same way when it's PRAM battery died, no advance warning, no wrong date and time, just suddenly dead. You can probably get one at Radio Shack and they're only $10-$15.

4JNA
Jul 4, 2010, 11:00 PM
really sounds like a dead power supply to me.

if you don't get results from any of the other reset/battery links, you might look at replacing the power supply.

if you don't want to spend the crazy money for an apple replacement, you can use a standard ATX $12 supply after moving a couple wires. long live the splice and electrical tape! :D

best of luck with the repair.

hewler
Jul 5, 2010, 12:09 PM
The only other thing that I can think of beside the obvious dead power supply is that maybe it needs a new PRAM battery. I can't explain how or why this would of coincided with the pulling of the plug, but sometimes things are just a coincidence.

I have a Bondi Blue G3 iMac that behaved the same way when it's PRAM battery died, no advance warning, no wrong date and time, just suddenly dead. You can probably get one at Radio Shack and they're only $10-$15.

I bought a new battery. It did not solve the problem.

DewGuy1999
Jul 5, 2010, 12:12 PM
I bought a new battery. It did not solve the problem.

Try resetting the PMU now that the battery has been replaced....

hewler
Jul 5, 2010, 01:40 PM
Try resetting the PMU now that the battery has been replaced....

I have tried. There is no reaction at all. :(

hewler
Jul 5, 2010, 01:42 PM
really sounds like a dead power supply to me.

if you don't get results from any of the other reset/battery links, you might look at replacing the power supply.

if you don't want to spend the crazy money for an apple replacement, you can use a standard ATX $12 supply after moving a couple wires. long live the splice and electrical tape! :D

best of luck with the repair.

Do you know how I can test the power supply to make sure that it must be fixed? Then if I have to replace it...how can I do it?

666sheep
Jul 5, 2010, 02:10 PM
From that what you wrote it could be PSU (like mentioned before) or simply front panel board. Remove fpb and inspect for visual damages.
To test PSU, you can try ATX test trick:http://www.duxcw.com/faq/ps/ps4.htm
But you need to determine which exactly pins you need to short-out. This vill be helpful: http://www.outofspec.com/frankenmac/wire.shtml If you don't feel skilled enough to do it, remove PSU and take it to nearest electronics shop/repair. Take with you this linked pinouts diagram, it should be no problem for them.
If PSU will be working, it'll be front panel board.

mdavies
Jul 5, 2010, 02:14 PM
I know that with my G4, the power button can be hard to press enough to start the computer. Do you have any PCI cards? I'm not sure if that will help, but when I was trying to boot 10.4 on my G4, I took out my USB hub and it booted the DVD, whereas before, nothing would happen.

kbfr08
Jul 5, 2010, 02:29 PM
Usually if a device goes bad, it won't spark when you plug it into the power outlet. Listen for a click when plugging the mac into the wall outlet. If it doesn't spark at all, it's most likely the PSU. If it still sparks, test the other parts first, but I wouldn't rule out a bad component in the PSU.