Power supply or logic board failure

First time post, long time Mac user (since 1983). My older iMac G5 1.8 GHz Power PC (ALS) occasionally fails to start when I press the power button or the internal power button on the logic board. The only solution is to unplug/plug the external power cable where it meets the power supply housing (not at the outlet). None of the capacitors seem to be bulging on the logic board, LED1 always lights up, LED2-4 fail when there is a problem but are normal after unplug/plug routine. Noticed that there was no internal Lithium battery where one is supposed to be, but this has been the case for 5 years, so this is probably not the issue. I suspect the power supply. It's an old iMac with plenty of leg left and will be used as a second computer in the home. Any ideas? I don't have a volt meter, but am willing to get one if the test points are easy to get to (I'm not an electronics wizard).

Welcome To Discussions - If resetting the SMU, which is in effect what you are doing, solves the problem and the caps look ok, then the prime suspect would be the power supply unit. They are not expensive, check out [synaptech.com] for prices or[welovemacs.com] whcih will also give you instructions on how to replace it.
It would probably be a good idea to replace the battery it's CR2032 3 volt lithium button, easily obtainable at Radio Shack or similar places.
Let us know how you make out,

Similar Messages

Power supply vs. logic board? turns off in sleep mode.

My imac g5 (2004 - 1st generation?) is either turning completely off or going into some un-wake-up-able mode after it's put to sleep. (I have to switch off/on the power strip and turn the computer on all over again.) And sometimes if it's sleeping (power light pulsing on front) it may or may not wake from sleep by pushing the power button. Often touching a key in that circumstance will cause it to crash, so I've quit using that altogether as a method of waking it up. I've reset the SMU a number of times throughout the past few months and it has not cleared up this problem.
Last night after I put it to sleep it switched in to the un-wake-up-able mode. I could still hear something running (not a fan, just an electrical hum) where it seems like it's crashed and can't shut itself off. I had to turn off the power and try to turn the computer back on. It wouldn't respond the first couple times. Then the power light glowed for a while but it still didn't turn on completely. After a few more minutes I tried again. Maybe I held the power button for too long, but I heard a long single beep, the fans whirred, and then everything started up as usual.
I've read a number of threads seemingly related to these issues, but am now not clear about whether this is a power supply issue or a logic board issue. I have yet to open the back and check for bulging capacitors. Just thought I'd ask here first.

I am having a very close issue too (posted also in a more recent thread about power button not functioning). My old iMac G5 20 inches got a power supply that went bad two years ago. I had it replaced and all went fine until two weeks ago.
My wife was using it, while I was away: machine shut down with a 'pop!' sound.
She tried to start it up again, but after pressing the button a couple of times - the last one longer - she had a long strong peep. The machine went on for a while and then off again. Scared, she left it off.
After checking, no reported issue seems to fit to the problems shown: power supply is working; logic board too. The machine is working fine, but on sleep, it dies out. While doing tasks, at undetermined times, it shuts down with a 'pop!'. Sometimes you can restart it immediately. Sometimes you can't and have to wait one or more hours. No evidently bad caps on board, led check returns 1 (no 2 flashing or attempting to turn on) with dead computer, otherwise all working fine. Hardware test also passed. Console messages have nothing relevant or clearly understandable to offer.
Still can't figure out a solution. Many user are pretty fast in suggesting to bringing the machine to Apple. Unfortunately not all around the world we have/need cars. And getting the 20 kg of iMac by feet/metro to the shop it ain't such a nice walk. When I fried the power supply, there was no sufficiently large box on sale to pack the computer and have it send to the shop. I had to wait for the technician - on a convenient day - do drop by and take it (and he knew he was going to repair it)!
Will post, if I have further developments.

What do you think-Power Supply or Logic Board??

I came across a used dual 1.0 GHz MDD G4 that will not start. When the power button is pressed, the power LED will light and then go out. There is no chime and the fans all come on incredibly loud and fast. The logic board has a small red LED between the CPU and RAM slots. Does the red light mean the board is working or good?
I've swapped CPUs and got the same result. If it was a power supply issue, would the fans and logic board power up like they do? I've put a disc in the drive and can hear activity, but nothing ever happens. Also the power supply looks to be smaller than the other MDDs I've used. It also has a large separate fan at the end towards the front/speaker area.
At the same time since the logic board has the red light, it would seem that it's working also. Right? I just need help deciding what to replace next. Thanks in advance.

Here is a link to the front panel issues in general:
http://www.xlr8yourmac.com/tips/MDDps_mods/MDD_PSMods.html
The front panel with the mirror doors was off. I used a small screw driver to >push the small start up button
Thus you did not disconnect the front panel BOARD. It has it's own connector to the motherboard. If you disconnect it and then short the green lead (Powerup) on the PSU connector to the adjacent black one (GND) you are bypassing the front panel button for booting. Do this only at your own risk if you have a solid electronic experience.
Here is a helpful pinout scheme:
http://www.smalldog.com/newsarchive/techtails_display.php?id=44
Hans

Power supply or logic board?

We had a funky power failure last night, and now my iMac G5 (17", 1.8 GHz, about 2 years old) is dead. Push the button, nothing happens.
I opened the case. The #1 LED is on, but it's not on solid. It's varying in intensity at a rate of a few cycles per second. Not really flashing on and off, but flickering. I've never noticed that before--I thought it was on solid when I've looked previously. Am I right about that?
The internal power button and PMMU reset button have no effect. Also, if I put my ear close to the power supply, I hear a "chirping" noise.
Any thoughts? I'm guessing it's the power supply. Any ways to test it aside from substitution? I have voltmeters and an oscilloscope and know how to use them, but I don't know where the test points might be.
TIA,
Neil
iMac G5 Mac OS X (10.4.8)

rbneil-
Take a look here.
It sounds like your power supply is dead. Apple will
repair it under the extended repair program if you
are covered.
The light should be on steady from what I remember.
That is a clue for sure.
Luck-
-DaddyPaycheck
Checking the link, it seems that the recall program only applies to the 20" model. Mine is a 17". Are you aware of Apple extending the warranty at all on that one?
Neil

2011 Macbook Air - Multiple logic board failures - possible causes?

I have a 2011 i7 macbook air - 7 months old. About a month ago I went to use the computer after allowing it to sleep and it was totally dead. Apple authorized repair center said the logic board failed and needed to be replaced. Fast forward a month and I finally get the machine back. It works fine for 6 hours, I put it to sleep, and soon as the screen went out, I hear a pop, fizzle, then the machine is dead again. The authorized repair center wants to replace the logic board again, which should get me up and running, but its not likley that that is the root CAUSE of the problem here, since it happened twice now. I suggested to them that perhaps the power adaptor, battery, or some other component is the issue and they don't think so. I'm located overseas, and every repair attempt takes 1 month b/c of parts (total joke if you're listening apple!!). My biggest concern is that they replace the logic board again, I'm out of commission for 2 months now, and it just fails again. Does anyone have any suggestions on the possible causes of this problem?
As FYI - I'm using the same power outlet and power strip with another laptop and haven't had any similar issues. Thanks for the help!

I have logic board problems too. I have had a late 2010 mac book air for 2 and half years. Its been a great machine in general - although it did go back within the warranty period for the track pad
Now it has logic board failure - symptons are the sound going and the battery is dead and it is unable to charge which means every time you put the power lead on the computer thinks it is starting from scratche.
I have been quoted over £400 for the repair! Like the above post I do not believe that this part should fail - and if it does then it is a major design problem and Apple should be doing something for us. I just dont know where to start.
I have used macs for 14 years and owned eight along the way. Most have them have lasted many years with full functionality the record was my G3 imac which was still working after 13 years.
I really cant believe the situation I am in and rather think I have bought my last mac!
alistair

IBook G3 start-up issues, possible logic board failure?

For the past few months the screen of my iBook G3 has been skipping and flashing and jumping at random times, quite often. If I move the screen to and fro it usually stops. I assumed this was just a bad connection with the LCD display and have basically ignored it.
Today, however, my screen froze completely while I was running Safari. Even the finder was frozen so I had to turn off the iBook by holding down the power button. When I restarted, it went through the usual start-up motions but after the grey start-up screen, it went to a blank blue screen. Only the mouse's cursor showed up at this point and nothing else. I was not asked to log in. Nor could I see my desktop.
I was just now browsing this board and found that the jumping screen issue I've been dealing with may have been logic board failure. Could this new blank blue screen problem also be a symptom of that? Or is it part of an overall hard drive failure?
The computer is quite old. I bought it in early 2002 and there's only about 2GB of space left on it at this point. So is it possible that the hard drive has crapped out?
I'm trying to restart right now in safe mode but it's been stuck at the grey start-up screen with rotating dial for about 40 minutes. Don't know what to do and I'm a little distraught at the idea of possibly having lost all of my files.
Any advice is appreciated. Thank you very much.

Hi, Christopher. Welcome to Apple Discussions.
Try booting into Safe Mode. This will take quite awhile longer than a normal startup because it does a file check and repair of the hard disk.
If this works you will see your normal desktop. Once completely started up in Safe Mode, try to restart normally, and go to Applications > Utilities > Disk Utility. Click on the top hard drive icon in the left sidebar and note the S.M.A.R.T. status at the bottom right of the pane. What does it say?
Select the named boot volume in the left sidebar, ("Macintosh HD" unless you've renamed it). What is the hard drive capacity and how much space remains available on it? Repair permissions on it.
If Safe Mode doesn't work, you will need to try repairing the hard drive from your Tiger Install disc.
Every time you have to do a forced shutdown instead of a normal one, there is a chance of hard drive damage and you should repair the hard drive, either by booting into Safe Mode OR by starting up from the Mac OS X Install Disc by inserting the disc and restarting your computer, holding down the C key as the startup chime is ending. Then click 'Next' at the language screen and choose Utilities > Disk Utility and select the hard drive in the left column. Choose the First Aid tab. Click Repair Disk to test and repair the hard drive.
Once you have repaired the hard drive with either Safe Mode or the Install disc's Disk Utility, then start up normally and repair permissions from Disk Utility in the Utilities folder on the hard drive.
Here's hoping that a little hard drive maintenance will help. Good luck.

Hard drive and logic board failure

Hi everyone,
we have been suffering from 4 dead hard drives and one logic board failure in 20-inch intel iMacs (~2007) recently and last month the logic board and hard drive of a 2010 27-inch iMac (just out of warranty) just died.
Are there any known issues with the iMacs that Apple fixes even outside the warranty?

Frank: I have a 5 month old 27" iMac and the logic board on it just died as well as I was getting all kinds of kerner errors. I have Apple Care and although the cost to replace the product was $800 I am not going to have to pay anything. I did talk to someone else who also had a logic board go bad on him but I doubt that you will be able to get it fixed without having to fork over $$$

Macbook Air, Logic board failure, what happens to data?

Hello,
My Macbook Air died today with 90% battery and will no longer turn on. SMC and PRAM reset did nothing, it's completely unresponsive. I think it's a logic board failure. I have a question regarding a repair with Apple; I realise they will replace the logic board inside my computer with a new (or refurbished) board and the faulty one will be shipped to Apple. Considering the Macbook Air has flash memory on the board will this mean my data is now unrecoverable? I have everything backed up, I'm not worried. I have some err personal photo's of me and my partner in iPhoto and I'm wondering what will happen to the sensitive data.
Thanks for dealing with this lets say awkawrd topic

I don't think that your flash memory files are unrecoverable. That's because the logic board of the MacBook Air hasn't got the flash memory soldered. However, I don't know if Apple will replace the logic board, "recycling" your flash memory, or if they will install a whole new logic board replacing the flash memory, although the first option makes more sense and it would be the normal option.
Anyway, as you have a backup on an external drive, you don't have to worry about that

Logic board failure - the 6th

my ibook is a little over 2 years old and i just had my 6th logic board failure last night. i knew it was going to happen after 5 previous failures... and it will certainly happen again.
even though its rare, i've heard of people getting their ibooks replaced. i know its not apple's policy with this issue (and wasn't the 5th time it happened), and i don't have applecare, but i'm wondering if i'm just screwed here.
i plan to call customer service and tell them that i know sending it in again for the LB repair extension program will just lead to another failure. there is no reason for me not to completely assume this... that my computer simply does not have the reliability needed for me to pursue my class projects. last night i lost my homework and it will not be turned in on time today.
i'm just asking for advice, based on other peoples experience, and given my situation, should i pursue a replacement or just reluctantly purchase a new computer?
ibook - dual USB

How long will Apple keep covering these logic board repairs?
Is it indefinitely, or only for 3 years?
... because mine is in for its 3rd repair and it will be 3 years old in another 6 months - and I suspect it will only break again.
I was told by the Apple rep [from the division that would cover replacement] that they have only replaced iBooks for people who had the extended warranty.
So I offered to pay to he $200 that an extended warranty would have cost.
The rep argued that the other people's units had the extended waranty in place when their units broke.
So I explained that mine broke TWIICE within it's intial 1 year warranty - and asked why that isn't the same condition as he just asserted was requisite - at which point he diverted the subject of the conversation so as to not answer - I assume because my point was well made and he couldn't provide a reasonable answer.
If it were only that I have to repeastedly send it back for repair [assuming it will continue to be covered] but backing up and wiping the drive of private info and restoring it takes hours.
In my opinion the thing breaks because it's put under some stress when grabbing the case, and the case flexes. The reason I think that is so is because the symptoms can be made to happen or not [when they initially start] by flexing the left side of the case.
The situation leaves me thinking there is an argument that the product failed its original warranty of merchantability. So I'm wondering if I should just go to small claims near a apple facility.
When I even questioned whether a legal issue existed the apple rep threatened to terminate my call and hand me over to legal.
How can he do terminate my call if there is a program that promises to cover the repair? That made me feel even more that I need to seek other recourse now and not wait until it happens again.

Upgrading from 10.2 to 10.3 w/ history of logic board failure

Please forgive if this has already been asked but...
I have an IBook G3 that has had 2 logic board failures in the last 2 years. Is it worth upgrading to 10.3 (Panther) w/ my history? I cannot upgrade most applications ( Itunes, Safari, AOL...) b/c I'm not running 10.3. I don't have the money to upgrade but need access to these things.
thankx

You can just install 10.5, assuming the machine supports it. It needs to be fast (> 1Ghz) and have at least 2 GB RAM. Otherwise, you'll be spending a lot more time at your mother's.
Don't attempt an "upgrade" of 10.2. Back up the data, then reformat the drive, then install Leopard. Don't run any migration utility. Set everything up fresh. Reinstall updated versions of all software that will run on Leopard. The only thing you want to copy from the old machine are documents.

Hi, i have a MBP 13, late 2012. Its over an year old since purchase and now out of warranty. This morning the computer did not boot so i went down to apple store and they looked at it and said its a logic board failure requiring replacement worth£350

Hi, i have a macbookpro 13, late 2012. I bought it last year october and its an year old and now out of warranty. This morning the computer did not boot, so i went down to apple store and they looked at it and said its a logic board failure and needs replacement worth £350. The tech at apple store gave no explanation, why suddenly, my computer decided not to start at all and said to me it was a logic board failure for no apparent reason and requires replacement. I have maintained the laptop in a pristine condition. Now I feel I have been cheated. This clearly means the product is substandard as a £1100 laptop is not expected to fail in just over a year. My last laptop PC which was worth £450 served me for 4 years before it crashed and lived for another 2 years until I decided to get a mac. This is ridiculous. I don't have apple care at the moment which translates as pay to get it fixed. Anybody in my situation ? I want to sue apple for selling me a substandard good . Any thoughts? Should I go for another pc for £500 because there is no guarantee even after the laptop were fixed by apple for £350 it would last for another year. I need a reliable machine.

This morning my MBP just woke up from sleep and is working without any glitches. I don't know what to say about this.

MacBook Pro Retina Display Logic Board Failure

There are a lot of threads discussing the logic board failures in MBP's. I have a brand new MBP with Retina 2012 that failed due to a bad logic board. Apple is replacing the machine, but is this a bigger problem others are having?
Data backup/recovery has been an issue since Apple's policy prevents users from retrieving data from the working and intact solid state drive (SSD) attached to a broken MBP. It seems ridiculous, but it is true that Apple stores are NOT equipped with external enclosures to read data from a SSD like a spinning HD.

There are a lot of threads discussing the logic board failures in MBP's. I have a brand new MBP with Retina 2012 that failed due to a bad logic board. Apple is replacing the machine, but is this a bigger problem others are having?
Data backup/recovery has been an issue since Apple's policy prevents users from retrieving data from the working and intact solid state drive (SSD) attached to a broken MBP. It seems ridiculous, but it is true that Apple stores are NOT equipped with external enclosures to read data from a SSD like a spinning HD.

Logic board Failure after 2 years - Macbook Pro 13''

Hi! Does anyone had problems regarding logic board failure on Macbooks Pro 13''?
I've bought mine 2 years ago and it started to fail. I took it to the technical support and was told that the logic board was damaged and it had to be changed. The warranty expired last november, so I have to pay for it. The problem is the logic board costs almost the price of a new macbook pro.
It is not possible that Apple think it is ok that a notebook that expensive lasts only two years.
I'm in Brazil and here there is no Apple store. So I'll probably have to buy another laptop ( and sadly I don´t know if I'm going to buy a mac again... not with it lasting as little and being the parts so expensive. )

Hi! Does anyone had problems regarding logic board failure on Macbooks Pro 13''?
I don't have the problem, but it's been percolating on another discussion for several years now:
https://discussions.apple.com/thread/2675881?start=0&tstart=0
You might think about posting there, too, so others can read about your issue.

Two MacBook Air logic board failures in less than 8 months

Hi All,
I purchased a new MacBook Air in early 2011. 14 months later the logic board needed replacement. 8 months after that the logic board needs replacing again. I don't take the Air into extreme temperature/humidity environments. The computer has never been dropped or had anything spilled on it. This is the 4th latop I've owned since 1995, but all of my previous laptops have been PCs. Is this normal for Apple? Any suggestions on how to avoid yet anoter $280 repair (because of course the latest logic board failure is out of warranty from the initial logic board replacement 8 months ago...)?

Let me get this straight - you consider the need to have the logic board replaced twice in less then eight months on a computer that is less than two years old to be a good deal?!? Both logic board failures were diagnosed at an Apple Genius bar in person. It shouldn't matter if it was the hard drive, battery pack, or whatever. To have a major harware component and its replacement fail twice in a very short period of time is inexcuseable! I can understand the first failure - someone has to lose the quality control lottery. However, to have the exact same component need replacing twice strongly suggest shoddy manufacturing/rebuilding.
Are logic board failures so common on Mac Airs that the discussion is about the best repair price and not the frequent failure rate?

MacBook Pro won't start up... possible logic board failure?

I bought my MacBook pro in March 2008, 15 inch, and it is now out of apple care.
It freezes on start up on the white screen with the apple logo and the spinning thing.
Did hardware test and got error code 4SNS/1/40000000: TC0D - 107.500
Is this a logic board failure, or possibly something that could be fixed much easier and cheaper?
Thank you for any help.

whitdare4 wrote:
Did hardware test and got error code 4SNS/1/40000000: TC0D - 107.500
That error code is listed as a hard drive sensor error. It may mean that the temp sensor on the hard drive needs to be replaced, or the logic board might be at fault.
It could also get caused from another fault peripheral device as the code describe generally a "connection fault".
You should remove usb mouse or other usb devices and try to boot in safe mode to eject all attached drives proper.
Lupunus

Power supply or logic board failure

Similar Messages

Maybe you are looking for