Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Computer wont turn on

M

MDodd02

macrumors newbie
Original poster
Jan 13, 2006
15
0
A couple of days ago there was a power outage at my house. I think my computer was in sleep mode at the time of the outage. However, it may not have even been on. It is connected to a surge protector.

Now when I push the power button the light comes on, but the computer doesn't turn on. Usually there is a click, then the computer powers on. Now there is no click and lots of frustration on my part. What do you think the problem is? Thanks in advance.
 
MDodd02 said:
A couple of days ago there was a power outage at my house. I think my computer was in sleep mode at the time of the outage. However, it may not have even been on. It is connected to a surge protector.

Now when I push the power button the light comes on, but the computer doesn't turn on. Usually there is a click, then the computer powers on. Now there is no click and lots of frustration on my part. What do you think the problem is? Thanks in advance.
Click to expand...

1. What kind of computer is it?
2. Have you tried plugging it into a different wall outlet altogether?
 
baummer said:
1. What kind of computer is it?
2. Have you tried plugging it into a different wall outlet altogether?
Click to expand...

Oh, sorry. It is a G4 Desktop. I did try to plug it into another outlet in another room and it does the same thing. Everything else on the outlet still functions properly.
 
MDodd02 said:
Oh, sorry. It is a G4 Desktop. I did try to plug it into another outlet in another room and it does the same thing. Everything else on the outlet still functions properly.
Click to expand...

Ok, so a PowerMac then. Sounds like the power supply is blown, but then again you get a light on the front so that's rather bizarre. You could try calling an Apple Store and speak to someone at the Genius Bar and ask them.
 
baummer said:
Ok, so a PowerMac then. Sounds like the power supply is blown, but then again you get a light on the front so that's rather bizarre. You could try calling an Apple Store and speak to someone at the Genius Bar and ask them.
Click to expand...

Maybe I will do that. Where would I get a new power supply? Cost?
 
Before you start replacing parts, there are other troubleshooting measures to perform. A corrupted Power Management Unit could certainly cause the problems you describe. Resetting the PMU is easy, just a matter of pressing a surface mount button on the logicboard.

What G4 do you have? Speed?
 
aquajet said:
Before you start replacing parts, there are other troubleshooting measures to perform. A corrupted Power Management Unit could certainly cause the problems you describe. Resetting the PMU is easy, just a matter of pressing a surface mount button on the logicboard.

What G4 do you have? Speed?
Click to expand...

Sorry, I don't really know. I got it for free from my mom's work. It has a 40 GB HD, that is all I know. I am a PC guy, trying to get used to Macs
 
MDodd02 said:
Sorry, I don't really know. I got it for free from my mom's work. It has a 40 GB HD, that is all I know. I am a PC guy, trying to get used to Macs
Click to expand...

Go into the apple menu(top right) then go "about this mac" Click more info. Then we want the machine model and CPU speed. Also note what CPU type says(G3-G5)
 
trainguy77 said:
Go into the apple menu(top right) then go "about this mac" Click more info. Then we want the machine model and CPU speed. Also note what CPU type says(G3-G5)
Click to expand...

Ummm.... his computer won't turn on....... :p
 
trainguy77 said:
lol....that great!:D I think that is one of the funniest things i have done in awhile....I am sorry you are probable thinking.....this guys stupid.
Click to expand...

LOL. not stupid... we've all done it, i'm sure...:D
 
trainguy77 said:
Yeah that sounds like the PMU reset will fix it. I have heard of this before.
Click to expand...

This is accomplished by pressing the CUDA switch right? Will this switch be clearly visible?

I really appreciate all the help!!!!
 
Resetting the PMU Chip Procedure


1. Disconnect the power cord and check the battery in the battery holder (BT1). The battery should read 3.3 V to 3.7 V. If the battery is bad, replace the battery, wait ten seconds, and then reset the PMU (refer to the next step). If the battery is good, go to the next step.

2. Press the PMU reset switch (S1) once on the logic board. Do not press the PMU reset switch a second time because it could stop the PMU chip from responding.

3. Wait ten seconds before connecting the power cord and turning the computer on. If the computer turns on, go to the next step. If the computer does not turn on, there is something else wrong with the computer.

4. Run MacTest Pro and return the computer to the customer.


Note: This entire procedure resets the computer's PRAM. Be sure to reset the computer's time, date, and other system parameter settings before returning the computer to the customer.
Click to expand...

I got this document from apples site. http://docs.info.apple.com/article.html?artnum=95037 Be sure not to press the PMU twice or your computer may never work again. The button itself is very small. Look for a metal block on the motherboard that is about 1/4 inch by 1/4 inch this should be your PMU. If your model is a digital audio G4, I'm guessing because of the 40GB hard drive, the PMU switch is located near your battery.
 
Here I found a picture I have of my old G4. This may help. Untitled-1.jpg
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back