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Dead power supply?

Message #1 - Posted 2005/06/20 - Jessica M.

I have an old gigabit ethernet G4 I plan to give to a friend. Last night I unplugged it from a surge-protector and moved it into the living room. This morning I plugged it into a wall outlet and it won't power on. I opened the case, pressed the wee power-whatever button that's on the logic board, and still nothing. The power cable is fine as I tested it on my current G4.

Unfortunately, this G4 is no longer under the AppleCare warranty I bought for it. I live in New York City, and the "old reliable Mac shop" known as Tekserve charges $110/hr for service. They told me they would not install any part I brought in, that I had to buy a power supply from them if I wanted them to install it, a new one even -- they do not sell refurbished power supplies. Given the prices I've seen today online for power supplies, a new one is going to cost at least $200. So, that plus $110 (it could not take more than an hour to swap out a power supply) equals $310 plus tax. My friend doesn't have that kind of money, although she has a desperate need for the old G4.

So, on the off chance it's not the power supply, what could be the problem?

Message #2 - Posted 2005/06/20 - Adrian

Jessica M. wrote:

I have an old gigabit ethernet G4 I plan to give to a friend. Last night I unplugged it from a surge-protector and moved it into the living room. This morning I plugged it into a wall outlet and it won't power on. I opened the case, pressed the wee power-whatever button that's on the logic board, and still nothing. The power cable is fine as I tested it on my current G4.

Unfortunately, this G4 is no longer under the AppleCare warranty I bought for it. I live in New York City, and the "old reliable Mac shop" known as Tekserve charges $110/hr for service. They told me they would not install any part I brought in, that I had to buy a power supply from them if I wanted them to install it, a new one even -- they do not sell refurbished power supplies. Given the prices I've seen today online for power supplies, a new one is going to cost at least $200. So, that plus $110 (it could not take more than an hour to swap out a power supply) equals $310 plus tax. My friend doesn't have that kind of money, although she has a desperate need for the old G4.

So, on the off chance it's not the power supply, what could be the problem?

If it's like most other older Macs it will simply be the PRAM backup battery ... in fact I woould be almost certain that's the problem ... cheap fix.

Adrian

Message #3 - Posted 2005/06/21 - Jessica M.

Adrian wrote:

If it's like most other older Macs it will simply be the PRAM backup battery ... in fact I would be almost certain that's the problem.

Would it be a dumb idea to remove the PRAM battery from the G4 I use and put it into the old G4 for the sake of testing?

Message #4 - Posted 2005/06/21 - Jessica M.

Jessica M. wrote:

Adrian wrote:

If it's like most other older Macs it will simply be the PRAM backup battery ... in fact I would be almost certain that's the problem.

Would it be a dumb idea to remove the PRAM battery from
the G4 I use and put it into the old G4 for the sake of testing?

Okay, I went to Radio Shack and bought the proper replacement battery. Unfortunately, I've read at least five different methodologies of how long one should keep the battery in before powering up, whether or not the power cord should be plugged in, how long you're supposed to press the PMU button, et cetera.

While at Radio Shack I should have bought a voltage meter to see if the power supply in the G4 is dead.

ARGH!!!

Message #5 - Posted 2005/06/21 - Adrian

Jessica M. wrote:

Okay, I went to Radio Shack and bought the proper replacement battery. Unfortunately, I've read at least five different methodologies of how long one should keep the battery in before powering up, whether or not the power cord should be plugged in, how long you're supposed to press the PMU button, et cetera.

So, have you tried it or are you worried about doing it correctly? My own method takes no account of any methodology ... just plug it in!

Adrian

Message #6 - Posted 2005/06/21 - Jessica M.

Adrian wrote:

So, have you tried it or are you worried about doing it correctly? My own method takes no account of any methodology ... just plug it in!

LOL.

I was pointed at this excellent tutorial:

<http://tinyurl.com/93a2s>

I've gotten as far as pulling the RAM and redoing the process, and the machine is still dead. Now I suspect the front logic board is hosed.

-( And, of course, Tekserve won't sell me any of these parts without

getting to install them.

Message #7 - Posted 2005/06/21 - Adrian

Jessica M. wrote:

I've gotten as far as pulling the RAM and redoing the process, and the machine is still dead. Now I suspect the front logic board is hosed.

-( And, of course, Tekserve won't sell me any of these parts without

getting to install them.

So I take it that you tried the new battery without success?

Adrian

Message #8 - Posted 2005/06/21 - Jessica M.

Adrian wrote:

So I take it that you tried the new battery without success?

Yep...did as the that tutorial instructed and I've got bupkis.

What is so weird is whenever I plug the power cord back into the G4 -- the other end of the cord plugged into the wall -- my apartment experiences that strange electrical current surge, like when you plug a microwave oven back in? Lights dim for a nanosecond. So if the power supply didn't have any juice, would that happen? Maybe! I read today a power supply can exhibit partialities it's working just fine, but in reality is ruined and needs to be replaced.

But all I did was leave the danged thing unplugged for a couple weeks! And now this! What worries me most is the whole PRAM battery/CUDA switch activity hasn't worked.

Message #9 - Posted 2005/06/21 - Adrian

Jessica M. wrote:

Yep...did as the that tutorial instructed and I've got bupkis.

What is so weird is whenever I plug the power cord back into the G4 -- the other end of the cord plugged into the wall -- my apartment experiences that strange electrical current surge, like when you plug a microwave oven back in? Lights dim for a nanosecond. So if the power supply didn't have any juice, would that happen? Maybe! I read today a power supply can exhibit partialities it's working just fine, but in reality is ruined and needs to be replaced.

But all I did was leave the danged thing unplugged for a couple weeks! And now this! What worries me most is the whole PRAM battery/CUDA switch activity hasn't worked.

Excuse me for this suggestion, but is there any chance the new battery is the wrong way round (or dead on arrival)?

Adrian

Message #10 - Posted 2005/06/21 - Jessica M.

Adrian wrote:

Excuse me for this suggestion, but is there any chance the new battery is the wrong way round (or dead on arrival)?

Yea, it's in right...I'm going to take the new battery back to Radio Shack in the morning and have them test it.

Message #11 - Posted 2005/06/22 - Jessica M.

I haven't gone to Radio Shack yet this morning, but looking at the battery I bought there yesterday I notice the manufactured date is June 2002.

Dead-on-arrival, Adrian? Could be! I'm flabbergasted that store would sell such an old battery, despite how long it's supposed to work.

Message #12 - Posted 2005/06/22 - Adrian

Jessica M. wrote:

I haven't gone to Radio Shack yet this morning, but looking at the battery I bought there yesterday I notice the manufactured date is June 2002.

Dead-on-arrival, Adrian? Could be! I'm flabbergasted that store would sell such an old battery, despite how long it's supposed to work.

Could be it ... though some batteries do have a long shelf life. All the standard alkalines I have seen recently have a "Use by" date as well as a manufactured date (5 years ahead on a pack I have just now). I don't know for sure how the lithium computer types last sitting on the shelf. It certainly seems worth getting them to test the voltage under load, in case you were sold a dud.

Adrian

Message #13 - Posted 2005/06/22 - Jessica M.

Well, the battery I bought yesterday is fully juiced. I also asked the kind Radio Shack counterperson to test the battery I took out of the gigabit G4, and it had just over 3V of juice.

So I guess I'm down to the power supply and front logic board. I wish there was a way to test both before making a decision on whether or not I should pay to have it repaired. :-(

Message #14 - Posted 2005/06/22 - Adrian

Jessica M. wrote:

Well, the battery I bought yesterday is fully juiced. I also asked the kind Radio Shack counterperson to test the battery I took out of the gigabit G4, and it had just over 3V of juice.

So I guess I'm down to the power supply and front logic board. I wish there was a way to test both before making a decision on whether or not I should pay to have it repaired. :-(

... some people find that sacrificing a live chicken can improve the liklihood of a successful outcome ... ;)

Adrian

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