HELP!! PowerMac G4 won't turn on
 

Hi,

I've been having a recurrent problem with my PowerMac G4 400 AGP, when I turn it off, it sometimes doesn't turn back on. The first few times I had this issue, I was able to turn it on after a couple hours. The problem is getting worse, with up to 24 hour periods without being able to turn it on (I'm writing this from a PC... yuck!). I've been resorting to setting it to sleep instead of shutting down, but I can't have it on forever.

I checked Apple Support site (www.info.apple.com) and I found a few solutions, the first is to check the power cord which of course works fine. The second thing I tried was checking the battery. After removing it I was able to read 3.9 V, so I guess it's fine, though a bit above the theoretical reading of 3.3 to 3.6V. After replacing the battery I clicked on the PMU reset switch. I also tried removing my Adaptec SCSI card, but that doesn't seem to be the problem either.

None of this solutions has proven successful, and I don't want to take it to Apple Support Mexico, because they will charge me a lot just for looking at it, and they'd probably suggest to replace the logic board -which I am pretty sure it's not necessary, because when it turns on it works fine.

Any ideas will be greatly appreciated.

Jorge

Are all cables inside the Mac attached correctly and fully?

Detach the power cable from the logic board and clean the connectors, then replace it. (Obviously, don't clean the connectors with water! ;) )

I find a new paintbrush (used lightly) will clean a logic board and its connectors just fine.

Still not working...
 

Thanks for your reply. I disconnected and cleaned all the connectors (power, ide, hard drive and one that comes from the power button) but I am still unable to turn on my G4. I also tried removing all the additional stuff I had: my second hard drive, additional RAM, my Adaptec SCSI card and my Pioneer DVD-RW.

I do not believe the problem is the power source because it's supposed to be redundant and I have no indication that it has failed. The computer was working perfectly one day ago.

Any additional thoughts are most welcome.

When you pressed the CUDA reset button, did you press it an let go right away? I've always been told that you should press it and hold it down for a few seconds and then let go.

I don't know that that will make much of a difference, but figured it couldn't hurt to throw that out there. :)

Good luck!

G.--

Have you recently installed OS X 10.2? Also if the cuda reset doesnt fix the problem you may have a defective front panel board (its the board the power switch connects to).

If you recently installed OS X 10.2 with out running the firmware updates you can get power issues, and no video issues like this. make sure you are running firmware version 4.1.9f on your mac G4. Hope that helps.

Thanks for all your comments, this is by far the best Mac forum. I posted this message in two additional forums to no avail.

I finally got my PowerMac to turn on again. Some details in case anyone has a similar problem.

I guess it could be a battery problem. I removed the battery last night before going to bed. I figured that if the PMU had stopped responding it might reset itself without the battery (just my conjecture). The PMU is apparently powered by the battery. Anyway, today I placed the battery and pressed the PMU switch. After closing and reconnecting, it finally turned on. For the time being I will leave it on for the next few days, at least until I get a new battery (not an easy task in Mexico). I've got a UPS so power failures might not be a problem.

I'm not sure if my solution had something to do with it.

BTW, I guess the firmware is not the issue since I have 4.2.8f1 installed. I have been using Jaguar since it was released, but thanks anyway.

cool, i have seen a lot of problems lately when people do not update their firmware. As far as the PMU being powered by the battery, I believe the battery just stores the info when the unit is not powered on. Therefore a defective battery should not cause the powermac to not boot up, but everytime you reboot it all the data in the PMU will be set back to default (e.g. time/date). It takes a 3.6v battery which if you cannot find in mexico I am sure you can get it online or through apple.

Same Problem
 

Greetings I'm having the same problem, or at least similar...

If I decide to move my mac, from home to the studio, and try to power on, I get nothing.
48 hours later, it will power on. I've tried everything even swapped the battery from an old g3.
I've been through this a few times so I'm confident it will power up again. It's just annoying having to wait. Anyone have a clue of what's causing this?

I've got the same problem. My G4 won't turn on after a power failure. I guess I'll keep waiting and see if it decides to get it's act together. If anyone knows a reason for this is a cure I'd really appreciate it.

Reset the hardware PMU by pressing the small button near the PRAM battery ONCE briefly. If you're not sure that you pressed it, don't press it again until ~15 seconds have elapsed.

If that doesn't fix it, replace the PRAM battery.

Trevor

Thank you so much for the advice Trevor. My Mac eventually turned on after letting it sit for about 6 hours. My computer wouldn't turn on and I had to return the laptop I was borrowing so couldn't get in to get your reply. The same problem will probably happen again when someone switches the power off or there is a power failure so I'll keep your advice handy.

Does anyone know why this happens? I have a PowerMac G4... had it for 7+ years. Nothing has gone wrong until a week ago. It won't turn on at all. No power, no fans, no lights.

I changed the PRAM battery and still nothing. It was on, I went outside - next thing I know, it's shut off. It has not been ab le to turn on since then.

I will try leaving the new battery out over night. I was just hoping to get some answers as to why this happens... all of a sudden.

Thanks,
C

And have you reset the PMU? Directions are above in post#10.

Trevor

Yes, replaced the battery, hit the button, took the battery out and let the computer sit 24 hours. The difference between others is my computer does not turn on at all. There are no sounds of fans and no lights turn on. I called a technician and he said it could possibly be the logic board or the power supply. Do you know how much that would cost?

For a PowerMac G4, a replacement motherboard would cost more than buying a used entire replacement PowerMac G4 on ebay.

On the other hand, the power supply might be cheap. You'll have to tell us exactly precisely which PowerMac G4 it is.

Trevor

What is the difference between a mother board and logic board?

Power Mac G4 (PCI Graphics) - (Graphite G4). I believe this is the one that I have. I purchased it around '00-01.

I am thinking about taking it in today. It's $45 just for them to check it out. After than, it's $75/hour + parts.

I am not sure if that model was correct - this is what it looks like. Hope it helps:

http://en.wikipedia.org/wiki/Image:G...G4Interior.jpg

http://en.wikipedia.org/wiki/Image:G...G4Interior.jpg

There is no difference. Some people call it one, some call it the other.

I believe that that PowerMac G4 Yikes! uses the same power supply as the Blue and White G3, which uses a fairly standard ATX power supply with some minor changes. More information about the differences are here: http://www.xlr8yourmac.com/systems/B...X_PS_swap.html

It should be an inexpensive power supply, if that's what the problem is.

Trevor

It could also be the front panel board, which is basically the power switch. Does the machine light up and do fans spin at all?

No lights, no sound... no power at all. I even tried to see if I could hear anything with the panel open, but heard nothing. It's with the techs now, so I am hoping its just the power supply.

If I decided to get a new Mac, doubtful, but a possibility. Could I use my old hard drive as the 2nd hard drive? Would the older one work with the new systems?

So, how inexpensive is inexpensive? 100 bucks? You were saying the logic board is expensive - 500 bucks? I don't know if it's worth while getting a new mac... I could use one, but it's not like my buget is set for 3K right now... we will see what the techs say and I will get back to you all. I guess the "Yikes!" is for how old my mac is, huh? It has treated me well - lasts longer than any PC I have ever owned... it's somewhat faster as some of the new PCs... or so I think.

Power supplies for your computer on ebay:
$25 Buy it Now http://cgi.ebay.com/Apple-Mac-Powerm...QQcmdZViewItem
Starting Bid $10, or $21 Buy it Now http://cgi.ebay.com/Apple-Power-Mac-...QQcmdZViewItem
Starting Bid $22, or $28 Buy it Now http://cgi.ebay.com/Apple-Power-Mac-...QQcmdZViewItem
Price $17 http://item.express.ebay.com/Compute...mdZExpressItem
Starting Bid $14, or $18 Buy it Now http://cgi.ebay.com/Apple-Mac-Powerm...QQcmdZViewItem

There's lots more. Search ebay.

Trevor

I wouldn't want to guess. Feel free to ask your preferred Apple Authorized Repair Center if you want a heart attack.

On the other hand, it's possible you could get one for a good price used on ebay, I just suspect that good price will still be more than buying an entire new (for you) Yikes! computer, complete with all of the other bits.

No, it's been a Yikes! ever since it was first released. Actually, as Yikes! was the Apple code name, it's been a Yikes! in secret ever since it was conceived. Apple's official name is Power Mac G4 (PCI Graphics).

The two theories that I've heard about Apple's meaning of the Yikes! name are
1. They got it to market really quickly by just slapping a G4 processor into the same computer as the Blue and White G3. This was a scary idea, but it worked.
2. Early buyers of the Yikes! should be afraid of it because the Sawtooth was coming to market in very short time, and the Sawtooth had a new motherboard with a superior architecture.

Probably both of these are wrong, and some Apple employee somewhere who knows the truth is laughing at both of these theories.

Trevor

Thank You!
 

Trevor, Thank you for your suggestion to press the little button next to the battery. It did the trick. Why doesn't Apple tell you sh-- like this? Perhaps because they want you to do what I was ready to do, which is go out and buy a new Mac. Oh well, that new purchase will have to wait until something really goes wrong. Thanks again!

Hi Andrea,

Apple does tell you about it if you look hard enough: http://search.info.apple.com/?search...%20reset%20PMU

But I suspect that it is not more widely publicized just because for desktop Macs it usually involves opening up the computer, and Apple doesn't particularly want you to open up the computer.

Trevor

power on issue with g4 ibook
 

I've had my ibook for about 3 years now and just had the logic board replaced last year. It will not turn on. I've done everything mentioned here and on any apple repair site I could find. I think it is the power button. It has been getting harder to use for a couple of months. Can I just get a replacement for the switch? Or do I need to get a new logic board? I read an interesting comment from someone who used a paper clip to make a power switch for a 12" ibook. Mine is a 14". I'm not going to pay 500 for a logic board when I can get a new mac book for 1000! I'm not ready to buy the new laptop yet, but I may have to if I can't figure out how to get this one turned on. I travel a lot and have to turn the computer off when going through security at the airport. Any ideas??
Thanks,
frustrated in Wisconsin

I know this is an old thread but...
 

Did anyone ever come up with a permanent solution to this problem? I have been having this problem with my G4 Gigabit dual 450 for a while now and the thing won't turn on at all now. I am thinking about buying a parts G4 on Ebay or something but I'm not sure right now. Gonna do some of the suggestions here and see what works, but I can't help but think that there is a permanent solution that will keep us from having to reset the PMU or pull the battery every time there is a power failure.

It really doesn't matter if there is a power failure. I've unplugged the machine due to storms in the area and had the same problem. It's when power is cut to the unit, whether it is off or not. Anyway. Anything anyone has for a permanent solution would be appreciated. This has been such a great computer for the last 8 or so years.

Thanks.

:rolleyes: I'm ashamed to say to never got back to thank you for your advice. I reset the PRAM as suggested and haven't had a problem since. :)

Slight variation, same problem
 

Hi,

My G4 PowerMac has a similar problem. I can warm boot the machine with no problem but as soon as I shut it down completely it will not power up (no lights, fan, nothing). I replaced the PRAM battery already. If I unplug all the cords on back (power, monitor, network, etc), wait a few seconds, and then plug it all back in the computer will fire up just fine.

I first thought that pressing the PMU Reset button was bringing it back to life but prior to opening the case I was unplugging everything from the back. So, the last time it wouldn't power up I did not press the PMU Reset but just unplugged everything as I described above and it powered up.

Any suggestions?

I got the same problem
 

I have the same problem and Reset PMU fixed the problem.

Thank you all for the info. I knew it would be out there some where. I love my Dual 450 MHz PowerPC G4 (kindly referred to as "Gretel" i.e Hansel and Gretel). I didn't want to see her go. I'm going to get a new battery tomorrow!!

re HELP!! PowerMac G4 won't turn on
 

This forum is excellent! My good old PM G4 1Ghz wouldn't start until I applied the Reset PMU remedy suggested by Trevor. Now it's working again :) but I'll replace the battery too, perhaps the source of the problem. I've been noticing for the past couple of months a white flash on screen, in the form of a line, lasting a fraction of a second, perhaps a sign of a tired battery?

PowerMac Quicksilver with start problem
 

Hey All,

I've been pulling my hair out even after reading all the problems everyone else is having with startup.
My problem has a slight variation, after getting the "power down or reset computer" msg I can't get mine to start difference is that all HDD's spin up all fans are on LED's on Logic board are glowing but the power button light doesn't (well only when you hold it down) and USB gear (keyboard and mouse) doesn't work. And it will sit in this state indefinitley.

Anyone seen this before???

Quicksilver Powemac G4 won't start
 

I have the EXACT same issue. I have tried all the repairs in the thread including replacing the PRAM Battery and still I get nothing but the Fan and the LED at DS5 on the motherboard.:( Any other tips would be great. I however, have not replaced the power supply... yet!!

MACII

Wojtech,

I am having the same problem with the power button light. Quite Frustrating I asure you.
If anyone has any other tips I a listening.

MACII

In my opinion it's the power supply, I must have seen 15-20 with same problem.

my G4 mirror drive is in a coma
 

i have the same or similar problem.

here we go:

i can't boot my mac (it's a G4 Mirror Drive Doors, dual 1Ghz, Sep 2002).
i think it might be on it's last legs.

here is what's happening:

i turn on the power on my the mains.

the fan starts already, even though i've not booted it up yet ( has been like this for years - fan rarely going off by itself ).

i press the button on the front to boot it up (the button is also a little light that comes on when the g4 is on)

the light is on while my finger is pressed on the button... but! when i release my finger, the light immediately goes off again.
it does not boot up.
there is no start up sound.
there is never anything on the screen, at all - no signal.
and, for the first few attempts, the fan seemed to go into overdrive (v. loud).

i have already tried to reset PMU, and reset logic board by taking out little battery etc. http://docs.info.apple.com/article.html?artnum=95066

i tested the P-RAM battery from the logic board with a volt meter, and it still has loads of power (80 to 90% full).. so, i didnt replace it with new one.

and i have taken out the big heatsink (on top of the processors) . i cleaned the processor wih a dry art brush, n blew the dust away. re-asembled...
still no good. i press my finger on the on button and it is only lighting up while my finger is pressed against it.
no sound of cpu doing anything, again.

tried again... the fan has decided to come on full blast again. but it's still not starting up.

as for the power unit, if this was dead then how would the fans come on...
i assume they're not powered by that little half AA size battery on the logic board.?

my Amateur guess (so far) is that either the logic board or dual 1Ghz processors have died of old age.

oh yes,

when i press power button, and the fan is on full blast, and with no light on the power button, i thought that it was completely dead.

but... despite there being no light on power button, and not starting up...
i've just held the power button in for 5 seconds (which would normally shut it down if it were on & working ok) and the fan then went down to normal speed.

what would you call this syndrome? ... a G4 Coma? or just Kaput :)

Thank you for your patient reading

Mac G4 won't turn on HELP!
 

Hi,

can somebody please help me. this morning when i tried turning on my mac g4 it doesn't want to turn on. I tried plugging it just in case its battery drained. I let it charge for awhile after 10 minutes i tried tuning it on again. It still doesn't want to turn on. The fan works, the power cord has its light on when i plugged it to the laptop. But it wont go through the start up page or the page where you log-in..

can anyone please help me???
i need to use it within a day. cause i have an online test to be passed on thursday and i haven't finnished it yet.

I hope that you used a small amount of fresh heatsink grease between the heatsink and the processor?

Trevor

actually, TonyWong might have a solution.
Though i think some type of visual guide with photos / diagrams might come in handy.

see "post no. 14" here:
http://forums.macosxhints.com/showthread.php?t=52401