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Apple G4 Power Supply Woes?
Predius asks: "I, like many others based on forum hopping, have an Apple G4 desktop that has decided it no longer wishes to power up. I've replaced PRAM batteries, verified power supply voltages, pressed the CUDA switch, and done combinations of the above. Trying to start it just results in a blip of the powersupply fan and the power led on the motherboard flashes once. Every now and then it will actually boot, and when it does it's 100% rock solid, will reboot fine, etc. If I power it off, I get to play games again trying to power it up. Does anyone know how to manually start an Apple Gigabyte or later rev power supply? Standard ATX power supplies can be fired up by shorting the green PWR ON lead to ground, but Apple decided to be different. I await the collective's wisdom."
Did you check the blinkerfluid?
I have the same problem with my pc. I've had it since july, and i think it is based on humidity. when i crank the AC up in my room and close the door, it will take about 20-30 mins before it will start. it's not the temperature because it can be 60 degrees in the room, but will still not start if the humidity is too high.
Sounds like this may be a inrush current problem... maybe something is taking extra juice to start up, or the supply can't deliver the initial kick. A multichanel scope would help a lot to see that all voltages are getting to where they need to be in a reasonable time. Otherwise, try removing everything that you can and see if it comes on (drives, ALL ram, usb, pci cards, modem, etc.) - maybe eliminate it that way. Remember, a bad card (one that's drawing too much current) may not cause the system to fail until another good card is inserted and pushes the power supply over the threshold.
HIV Crosses Species Barrier... into Muppets
The last time a Mac did this to me it turned out not to be the power supply, but the battery that was bad. Note that this wasn't a G4, but an older PPC 604 model, so things may be different. For some reason when the battery was dead the machine wouldn't turn on, or when it did it would turn right back off. I'd replace that first because it's an easy and much cheaper fix.
-David
There. Now go play some cool javascript games!
Have you tried resetting the PMU?
Pop that sucker open (unplug first!) and there should be a little black button on the lower front of the logic board. "Reset pmu" will be printed on the board somewhere near the button. Push it for one second and only press it once. Let the box sit for roughly 5 minutes unplugged and then turn it on.
"My mother never saw the irony in calling me a son-of-a-bitch." - Jack Nicholson
...maybe you should, I dunno, take it in to be fixed. No, really, you've tried diagnosing it, and you couldn't figure it out. So, rather than take it in to be repaired, you decide to post your question on Slashdot? Seriously?
I mean, I guess that works for the editors, since you post made it up, but I don't think that this is such a common problem that it needs to be here for everyone to try to help with.
But since we're here, could anyone tell me why my Check Engine Light keeps coming on in my car? Also, there's a hole in my shoe that I've tried patching with duct tape, but that doesn't seem to work - any advice on that?
Sigh.
=Brian
There is nothing so good that someone, somewhere, will not hate it.
Especially if you are out of warranty. Apple describes it in support article 95039. The most frustrating part is that replacing the power supply is the last step -- they try to replace the CPU before checking the power supply. This means that you have to commit to purchasing a CPU if it is the problem child. My CPU (500Mhz G4) was ~USD900 last time I checked -- more than the value of the the computer at the time. All this is after you pay their diagnostic fee.
Don't get me wrong, Apple Care is wonderful, but once it expires you can be in for some expensive repairs...
I hate to ask the obvious, but since your machine is clearly working improperly in a manner that cannot be due to software, OS installation, disk formatting, etc....
Have you considered taking it in for service?
The friendly folks at the nearest Apple Store will be happy to take a look at it. If it's still under warrantee, or if you've invested in AppleCare, it won't even cost you anything.
"If I power it off, I get to play games again trying to power it up."
Sounds like Apple's game library noticably expanded!
"Derp de derp."
"I've replaced PRAM batteries, verified power supply voltages, pressed the CUDA switch, and done combinations of the above."
Look, there are many ways a powersupply can fail and still appear to have the correct output voltages. For instance, the powersupply has a power good signal going to the motherboard. The PS determines whether it's within its specifications, and when it is (some mS after actual turn on) it asserts the signal, and the motherboard comes out of reset. It could be that either the powersupply is not asserting the signal correctly, or that it is still out of spec.
But it could be a dozen other problems. Until you swap it for a known good PS, you cannot know for sure that the PS is good. (other than, perhaps, putting it in another good system and powering it up there)
Here is the pinout of a dual G4 powersupply. I suspect that the pinout is substantially similar. You may be able to force the PS on, but you'd have to find and assert the power good signal (I doubt that the supply doesn't have one - chances are they made this pinout with a multimeter, and there's no easy way to find the power good without a scope or analyzer)
But I suspect that you'll spend less money and time by simply getting a new PS and replacing it.
Please note that powersupplies contain many parts that fail over time. Aside from the obvious fan, the electrolytic caps eventually dry out, causing out of spec voltages, out of spec ripple, and out of spec regulation. You won't be able to see the ripple on the average multimeter.
Also note that computer hardware troubleshooting is a black art, and should only be practised by mages trained in this specialty.
-Adam
macintouch.com has great forums on Mac issues, i would say look/ask there or some of the Mac tech help mailing lists.
i know some older motherboards required you to hold the motherboard reset button for about 30 seconds if you ever pull the PRam battery out.
back to your first issue of manually jumpstarting a powersupply, dunno. sorry. just figured iw ould mention the motherboard reset button because i know somebody that got a lot of stress from not knowing that.
I've been looking to get a G4 rather than a G5 because of the large number of drive bays available in the G4 case (video editing). Could it be that the power supply doesn't have enough power to spin up all the drives in your system simultaneously?
If this is the case, TiVo hackers came up with a device to allow some of their units with less powerful hard drives to spin up two drives separately: the PTVupgrade SmartStart Power Supply Protector.
I have not used this device myself yet in a TiVo or Mac, so I can offer no testimonial, but the design concept is sound, and I've heard no complaints about it on TiVo-related forums.
Of course, you should first determine if it is the drives' load at spin-up that's causing your startup problems.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
I have a G4 Dual 400 (mirrored drive door) and had a similar problem. After numerous games, and since it was still under warranty, I brought it in. Four visits to my local Apple store later, it works. They replaced the power supply, memory, ram, processor, and finally after I demanded it, the motherboard (or "main logic board" in Apple lingo. It was the motherboard.
0 38
Turns out there's a known Apple TechNote on the mirrored drive door boxes that produces a power on, but unexpected results type problem. Here's the technote (iirc) or at least one similar: http://docs.info.apple.com/article.html?artnum=95
I HIGHLY recommend making a list of technotes that directly refer to and explain the problem in detail. Do what you can yourself. Go to an Apple store (make it a road trip if there isn't one near you - I'm in NY, US so it wasn't a problem), walk up to the "Genius Bar" and make them work for their famed support reputation. I've owned macs since sometime prior to the Quadra and when it doubt, Apple *will* save you should you ask the right way. Be nice. Beg. Your warranty is an intangible and can be extended by the manufacturer if it is a known problem and you plead your case correctly.
This is usually related to a bit more than the power supply and is absolutely a known issue.
Good luck. Chin up... and beg if you're out of warranty.
It's not so simple to just drop a new power supply into a Mac. The supply on the G4 Powermac is not, as far as I can tell, identical to or compatible with the standard ATX supplies that x86 machines use -- the part in question is both proprietary and expensive. Your advice would be perfectly reasonable if we were talking about an x86 box, but we aren't, and there's the rub.
I had a G4 that refused to boot, and when I brought it to Microcenter to be repaired they informed me that if it was a bad power supply, the part would be something like $200. When I asked if the $30 ATX supplies they have could do they job, the answer was a clear "no" -- which even they seemed disappointed by. In the end, the problem turned out to be the motherboard, not the power, and replacing that would have been about $500. I ended up getting a new G4 instead of paying that much to keep an old machine alive.
Unfortunately, my new Mac has exactly the symptoms that are described in this discussion: normally the machine runs just fine, but every now and then when I reboot it it will just refuse to turn back on. The power light will throb briefly, the power supply fan will spin up, and the machine makes a few other chirps & squeaks -- but it never gets as far as spinning up the hard drives, and the "Mac chimes" never get played. At that point, the fan willl keep spinning until you turn the machine off, but nothing further will happen. However, if it gets past that point -- if the hard drives turn on, and the Mac chimes sound off -- then the machine comes right up and there are, as far as I can tell, no other issues at all.
The only "solution" I've found so far, aside from not turning the machine off if I can help it, is to just be patient: Hit the button, wait for it to start. If it doesn't, turn it back off & wait some more. Try again. if it still doesn't work, wait longer. It seems to help a little bit if I make sure that the machine is completely stopped (no fan noise, etc) before trying to turn it back on again, but that's no guarantee -- it just helps the odds a bit. It's not just the quick turnaround though: once the machine sat off overnight & still wouldn't start up right away in the morning without going through the try, fail, retry nonsense for five or ten minutes.
Elsewhere in this dicussion it was suggested that it may help to hit the Power Management Unit button on the motherboard while the machine is turned off & unplugged. It's worth a try I suppose, but I'm a little unclear as to how this is supposed to help, or if it will help. Another poster points out Apple support document 95039, which seems closer to the mark and definitely sounds promising. I'll have to try those steps & see if it helps...
DO NOT LEAVE IT IS NOT REAL
Dude. It sounds like you simply have a blown-out power supply.
This happens ALL THE TIME with PCs. Of course, Apple has much tighter quality control, so this happens a lot less, but does happen nonetheless (I've seen several iMacs and G4 towers with dead PSUs).
Power supplies can die due to manufacturing defects (specifically cheap electrolytic capacitors), or due to bad power. If your building has bad power (you probably don't even know it), the life of your power supply will be easily cut in half (consumer-grade surge supressors and UPSes do little good against voltages which are constantly 'noisy').
-- If you try to fail and succeed, which have you done? - Uli's moose
Take the battery out and let the computer sit unplugged for a few hours. Then put the battery back , plug in power, and test. If this doesn't work try with the battery out overnight. I try this after everything else fails and was very happy to find this fix.
:-)
You are, of course, exactly right.
Still, it's not as bad as it used to be. As far as I can tell, the only really proprietary parts on a modern Mac are the CPU, motehrboard, the power supply, and maybe the video card. In the case of the video card, it's only "proprietary" because the systems are Open Firmware based (like Sun, SGI, and maybe some others), and the video card has to be able to talk to the rest of the system -- but it uses the same AGP bus that x86 uses, and my impression is that there's no reason that the "Mac" cards wouldn't work just fine if (say) AMD ever designed an Open Firmware based x86 platform.
Beyond that though, it's all standard hardware. Same RAM, same hard drives, same PCI bus for expansion, same peripherals on the USB & Firewire ports. And so on.
It used to be much worse than that, in the days up to the blue & white G3, with the Nubus architecture, "standard but exotic" SCSI bus for hard drives, etc. Moreover, above the hardware level, they've gotten very good about using standard protocols & formats for nearly all of the system, and have offered up their new developments to be used as open standards (e.g. Rendezvous).
While it's annoying that they can get away with charging so much for the proprietary parts that they still control, at least these parts are generally pretty reliablee & most people don't have any problems. And the rest of the system is just so much nicer than anything that could be run on x86 that I for one am willing to take a chance on what Apple has to offer, knowing that if anything does go drastically wrong, the fix can be ridiculously expensive compared to the same repair on the other site.
Everything is a tradeoff, ya know?
DO NOT LEAVE IT IS NOT REAL
1) Reset the Tralfaz Emulator
2) Hold the Grimes Conductor & the Simpsons polylead together
3)...
4) Profit!
This
...technical support queries. Pay for your own Apple Care and leave /. for the quality reporting that it provides.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
There was a revision of the G4 in August, 2000. The first ones off the line had power switch problems, giving almost the same symptoms. We had them all replaced under warranty.
One work around, find an older Mac USB keyboard that has a power button on it. Plug it in and see if the machine will start then. If so, you will need to get a replacement power switch.
More info available from ZDNet.
What, me worry?
Well, 5 years ago, I got a VIRUS on my PC and it fried the Motherboard... exactly why I have a house full of Macs now.
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They Are Vermin Feeding On Each Other's Feces.
I Hate \.
" If you actually believe that a Virus can "fry your motherboard" then you sound like the ideal / typical mac user..'
Not your motherboard so much as fry your processor. Several early motherboards that set the processor speed and core voltages in BIOS could be exploited in such a way that software on the system could also change the voltage and clock speed. Set the voltage another volt higher and the processer would be damaged.
I don't know the exact mechanism that the motherboard manufacturers are using now which prevents software from changing these settings while still allowing BIOS to do so (or only 'approved' software - such as Gigabyte's EasyTune utility), but the problem hasn't appeared since the mid-late 90's. Of course, the Intel processors don't damage as easily as they used to either.
-Adam
Actually, the CIH virus awhile back did kill motherboards. It wasn't "frying" it but it would corrupt the flash BIOS and therefore make the motherboard not bootup at all.
No no no! See how I put "proprietary" in quotes? Do you see how I mention that other vendors also use OF? Did you catch how I mentioned that there's nothing stopping AMD from adopting OF on their platform?
I realize that OF is an open standard. Really.
It's just that OF is a de jure standard, formally codified and supported by a variety of vendors, while the x86 spec is a de facto standard, consistent only with itself but, because it happens to be the platform used by 95% or whatever of the market, is the one that is dominant.
The fact that OF is more open kind of doesn't matter if the vast majority of systems out there are using something else... :-/
DO NOT LEAVE IT IS NOT REAL
My Power Mac G4 is on it's second power supply. The problem went away! And it's a Power Mac Gigabit, not Gigabyte.
I have had several issues like this. A factor to include is the Video card...if you have an Apple Studio Display attached to it. The ADC Connector provides 28V DC, I have seen an improperly seated video card or a loosely connected ADC connector cause power supply failure.
Don't know about G4s or desktops, but I'm now on my third dual-USB iBook external power supply. First replacement was covered by the warranty, but I just shelled out ~$85 for the second replacement today at the local Apple store. And the main logic board had to be replaced three months in. AND the little twist lock on the underside that releases the battery is broken and held in place with scotch tape. I love this laptop, but the build quality is not good.
just push it downhill, press the power button, and pop the clutch.
Ahem.
The Nubus architecture was not proprietary and indeed a non Apple standard.
It was developed for the Texas Instruments Nu Machine ( back in 1982 I think ) and was used in the Texas Instruments Explorer Lisp Machines.
and then the S1500 series of Unix servers introduced by TI in 1986 and sold to HP in 1992
So you see the Nubus was already an old bus by the time Apple started using it.
This sounds like the cheap capacitor problem that was affecting PC motherboards last year. My ABit KT-133 was experiencing the exact same symptoms you describe, it would work fine until I turned it off, and then it was a crap shoot if it would boot up again. Here's the /. article: http://slashdot.org/article.pl?sid=02/11/04/175121 0
I know it's an Apple, but if you can get a look at your capacitors, on the motherboard and in your power supply, see if they have bulging tops or any leakage. Mine were just bulging a bit, but it was enough to be a problem.
If it is a capacitor problem I'd be mighty pissed with Apple for buying such crap, especially at the prices they charge.
I stand happily corrected :-)
Still, it was an exotic standard, if an "official" one. Give me at least that much -- in the end, Apple seems to have been the main & only vendor using it... :-)
DO NOT LEAVE IT IS NOT REAL
The video card is only 100% proprietary if it has an ADC connector. You can flash some PC video cards and drop them in a Mac and they'll work (at least, this used to work with GF2MXes. Not sure what's different about ATI cards).
Mac CPUs *can* be replaced (ZIF socket), but what with the last few years there have been very few modules sold worth upgrading *to*. And it's not as simple as just buying a part from Motorola, as the L2 backside cache is kept on the CPU module.
Mmm...the Blue and White G3's were the first Macs to do away with nearly all of the old style Mac uniqueness. They had VGA video, USB keyboard and mouse (and ADB for older input devices), IDE drives, ZIF socket processors, etc. You could get SCSI in them, but it was extra.
As to this problem, it's most likely the motherboard. I can't count how many G4 wind tunnel mobos I've replaced in the last year. The problem with the powersupplies is mostly due to them not responding to the mobos fan cycling, making them run way too loud. Apple had a program to ship you a replacement power supply but I think it ended last June. Can't hurt to check with an authorized Apple repair center to see what programs might be out there. If enough people complain to Apple about a problem (you gotta' call and make a nuisance of yourself), they usually will try to fix your fairly new Mac and maybe put into place a repair issue, like the one they have with the 17" b/w monitors.
I drank what? -- Socrates
For replacement CPUs, check out Sonnet Technology and Other World Computing. Sonnet makes most of the upgrade chips and Other World has some great support for issues involving CPU replacement/upgrade.
I drank what? -- Socrates
After submitting the question, I resumed scouring the web and got a bit braver with my parts...
o nv ersion/G4_AGP_to_ATX_case_pg2.htm has the mods that get you 99% of the way there, you just need to supply 28v to finish the job on any ADC capible G4s. Once I figured this out I had the system booting off a PC power supply (and the 28v trickle from the G4 supply). I bench tested the G4 supply, and sure enough, shorting the power good, which should have fired it up just bliped the power. Based on the symptom set, it seems pretty likely this is whats affecting others. The test is simple, use a paperclip or something similar, short the green power up line to a black ground line, and see if the power supply fires up. If it does, it's the mobo, if it doesn't, its the power supply. No more throwing batteries sacrifical virgins at the problem while performing dark rituals around the CUDA switch.
After reading up on some G4 to PC ATX case conversions, and doing a lil guessing, I determined that the G4 power supply should use the same power up sequence as an ATX. What threw me off is earlier PC ATX power supply to mac conversions had to invert the power on signal, and I incorrectly assumed Apple did the same with the G4.
http://www.xlr8yourmac.com/systems/ATX_G4_AGP_c
And for those curious, the machine I'm building is a FrankenMac, assembled from random bits on eBay and my parts closet. I've TRIED talking to apple stores, but the instant they figure out its not a boxed apple, they tell me to pound sand. I've got $75 into the power supply, so I wanted to be ABSOLUTELY certain it was the culprit before canning it. Unfortunatly, while Apple will offer some simple diagnostic guidelines, they won't give you all you need to do this sort of work outside of an Apple authorized repair depot.
It's really simple. Here's how you do it:In your case, you might have written something like:Which is coded this way:The main beef I have with URLs that aren't made into links is that they are automagically cut in half by Slashdot's filters. So it's not enough to cut and paste them -- you have to remove the space in the middle.
Karma: Chevy Kavalierma.
this fixes my g4's boot problems every time
I fear nothing but my government. Vote Libertarian.
On some of the older models, you had to hold the button down for 15-30 seconds for it to work. But like he said, only press it once.
And i know you said that you verified the incoming voltage, so my only other trouble shooting suggestion would be to try it at a friend's house or at work.
I would be frustrated as hell if that happened to me. Almost as pissed off as I am about my Win2K notebook being unable to boot (hive file) after running a windows update. Just another reason why I love my G4 & jagwiiire
Yes, I am the typical HAPPY Mac User. I don't get viruses anymore.
I have a biege G3, a Lime Green Rev C iMac, a Powerbook G3 and 2 G4 Cubes. They are all connected via Ethernet, all with high speed internet. The iMac is in the living room connected to the stereo for playing my MP3 library from a firewire drive, that once connected to any machine can mount on any other machine. I also listen to streaming radio stations. It's so fun switching stations and tracks with the USB remote control! I connect my keyboard (musical keyboard) to the laptop and digitally record. I also use the laptop to watch DVDs on the digital projector. I use a stylus tablet and even have a three button mouse. (Logitech, $15, no drivers) None of these computers is EVER turned off and I have NO PROBLEMS. They all run SETI in their spare time I've never had any problems making any of this stuff work! And my newest Mac is over three years old! My house is wired like I could only dream less than 10 years ago! I don't even need a new computer!
So have fun downloading that latest patch from tinyFlaccid(R).
And for the record, after realizing half my files were gone, I ran a virus checker on that old-piece-of-shit PC, and it never booted again. It's in a box in my basement.
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They Are Vermin Feeding On Each Other's Feces.
I Hate \.
It's your front panel board, which is a user replacable part. Check article id 58748 at Apple Support.
It's not offtopic, dumbass. It's orthogonal.
Did you even bother to do any research first before posting here? theres dozens of websites that have instructions on adapting an ATX powersupply to power macs.
TRY GOOGLE.
My G4(2x867MHz,MDD) has exactly this same problem. I've reset the PMU -- it makes no difference. I've even taken it to the shop twice. Of course, it's always working by the time it gets there. :) It seems that by the time it cools off, it works fine again.
I also have the new (supposedly quieter) power supply for the MDDs. I haven't installed it yet because I'm afraid to add another variable to the equation.
Their advice in the shop: buy AppleCare -- we can't find it, but it'll probably be back!
Please help find my missing daughter: FindSabrina.org
There's a now-locked thread on MacNN in the PowerMac topic about this, and I've posted a number of success stories in that thread. Basically, most OEM (ie Sapphire or PowerColor) 64M Radeon 8500s will flash, but only if they're over a certain clockspeed. I've done two, one worked perfectly in OS 9 and OSX 10.1.x, but will instantly overheat if a program does OpenGL calls (which leaves 10.2 as a no-go). The 2nd card was a bit more expensive, but has been perfect.
IIRC there were some low-end 8500LEs that would just never work no matter what, and the 128M cards wouldn't work either, despite a number of people claiming they would.
The one big trick that a lot of people forgot to do was unplug the damn monitor when flashing it the first time. Just about everyone who left it plugged in got a permanently dead card or what's called "phantom monitor syndrome" where there's only one monitor plugged into the VGA port, but the card's convinced there's one in the DVI port, so you only get 32M of VRAM on your display.
It doesn't mean much now, it's built for the future.
This is really disappointing. My first Mac and it feels like a lemon.
The meme police, They live inside of my head
1. Try (Command + Ctrl + Power key) 2. Pull all third party RAM and cards. 3. Hit the reset switch on the logic board. 4. Replace the battery. 5. Reset the PMU. 6. If you successfully start the Mac, press (Command + Option + O + F) and type reset-nvram. press type set-defaults. press type reset-all. press hth, dion
I know this won't be of much help, but i've seen countless problems that can cause these issues (in both Macs and PCs). My own PC did this very thing to me about a month ago....changing the power supply fixed it right up. I've also seen a mac with a bad mobo that exhibited the same problem. As for other causes, i've seen bad bios chips, shorted wires, swelled mobo capacitors and bad house outlets or power cables. In short, take it somewhere. Either and applestore, or an authorized service center (i'm lucky to have one about 4 blocks away). Power probs are some of the hardest to track down due to the wide range of problems that can cause it. Good luck
Dear /.ers,
Like undoubtedly many anal retentive, abbreviation savvy others have done before me, I searched like a devil to find the meaning of what I then thought to be an acronym: CUDA. However, no such definition was to be found, and this is very rare.
On further inspection, I also found that Apple _consistently_ referred to the controller chip as Cuda, not CUDA, further strengthening someone else's theory that this is indeed a code name/nickname of some sort and not a pronounceable initialism (a.k.a. acronym).
So, fellow slashers, from now on, please be accurate and consistent (and above all respectful to future abbreviation savvy loonies) and _do_not_ capitalize all the letters in Cuda!
PMU, is of course another story. It is an initialism, though not an acronym, for Power Management Unit.
I've had three of these, they've all burnt out where the cable enters the plug at the computer end of things. The next time one blows I plan to get a 3rd party PSU, perhaps an iGo juice.
You may want to take a look around Apple's Power Mac G4 Discussions.
It's the ideal place to ask for help on these types of problems.
The Cuda IC is an integrated circuit on the main logic board of Power Mac G3's that provides several system functions, including
management of soft system resets
management of the real-time clock
software control of the power supply
G4's use the PMU99 power controller; most people call it the Cuda out of habit.
YOU are the one who purchased a G5 to get your work done. So, I suspect you could answer your own question.
That's exactly where both of mine died too. I didn't realize that there were 3rd-party PSUs out there -- thanks.
I had an identical problem with a Geige G3/233 MT. Zapping the PRAM 7 times fixed it. While the machine is off, hold Cmd-Opt-P-R, and press the power button. (It's easier if you get someone to help). You need to do this a few times, and it should take care of it. It's really not the PS, honest. Good Luck!