View Full Version : Imac G5 Midplane Replacement

17th June 2005, 10:22 AM
My (Rev A) iMac midplane has died as it seems :(
Lucky it's only 2 more days until warrenty expires so I gave apple a call and they're replacing it.

Just out of curiousity, does anyone know if they will replace it with the same Rev A logic board?

17th June 2005, 10:50 AM
as far as i can tell they are still shipping the rev a boards though the fact that anyone wwould call anything a rev a suggests that a rev b exists. in previous imacs it was required to replace parts like for like (rev a with rev a and rev b with rev b etc etc i think you get it)


17th June 2005, 11:14 AM
seems stupid really
I mean to me it seems that revisions of macintosh's are mainly to iron out problems with the board.
why would you replace it with the same revision? :/

17th June 2005, 11:28 AM
When did you get your iMac? Is it a refurb or ex-demo? Because otherwise iMac G5 warranties should last at least until September...

And I agree with macmate - even if you do get a rev B board, you won't be seeing any difference, and the processor will be the same - I would have thought that they'd be generous and replace older defective items under warranty with the current model, but if their replacement policy on iPods is anything to go by, despite supply difficulties they somehow manage to have enough part of older models around for warranty replacements...

17th June 2005, 11:32 AM
i think its fair to get a replacement part of the same model
you bought that model so why should you get a free upgrade ?

Rev b's have new video cards remember

17th June 2005, 11:37 AM
oh, I'm not concerned about the updates
I'd be happy if they had the problems that the rev a had fixed with just the old gear (graphics, cpu)

just don't really want it to happen again

17th June 2005, 11:53 AM
Thanks islayer - but I don't think it's a matter of fairness, rather it's a cost-of-manufacture issue.

I'm merely surprised that given their own manufacturing contraints and their supply chain (racing to keep up with demand and shifting production from one model to the next with very little ramp up, and barely any transition) that they would manufacture legacy models, given that it is for cheaper for them simply to ship out something from the current batch. Admittedly, they probably keep some surplus for warranty repairs - but for example, consider the incredible shortage of 20GB iPods last year (with several month waiting periods and offers of cheap/sometimes free upgrades to 40GB), yet when a friend of mine had to get one replaced for warranty repairs, her replacement appeared within a couple of days. Admirable warranty responsiveness, but surprising given their supply chain problems.

I do take your point about the video card - but if it's cheaper for them simply to ship out a current midplane assembly rather than CTO one just so that you only get what you originally paid for, they shouldn't be batting an eyelid at taking the cheaper option (and often do, though notable exceptions include the aforementioned iPod issue).

18th June 2005, 10:27 AM
Lets not forget about my iBook saga.

Also, take note. Never buy a Rev.A

If I buy a Commodore.. shoot me! No, seriously, if I did. I'd be looking at a Series II.

Everything I buy it always 2nd generation. The iBook being Apple's worst machine ever being the exception.

18th June 2005, 10:32 AM
I have a Rev A iBook G4 and I haven't had a problem with mine :)

*touches wood*



18th June 2005, 10:39 AM
I had the original clamshell and never had any trouble whatsoever with it
aside from it being a bit of a bastard to upgrade the HD to run panther
see: http://www.powermodell.com/random/ibook.jpg

18th June 2005, 10:59 AM
i need to make a correction. i thought he was talking of rev b of the motherboard for the rev a imac (which doesn't exist). in the early imacs they had difference revisions of the same board for the same model and hence this is what i thought he was talking about. these revisions had to be replaced like for like because they coupled with the power analogue video board which coupled with the crt (they used a few different brands) and hence had to be replaced like for like.

20th June 2005, 12:51 AM

I took mine in today to have the same problem fixed, so will let you know as soon as it's fixed. I'm hoping for a Rev B logic board, but not holding my breath.

20th June 2005, 09:23 AM
they already ordered it in danno?

20th June 2005, 07:24 PM
No Poppy, I'm not sure at the moment - I dropped it in yesterday (Sunday) and haven't heard fro them yet - I guess I won't find out until later in the week when they actually get the parts in.

22nd June 2005, 11:14 PM
Quick update on the iMac G5 midplane replacement situation.

Rang up Apple Centre today, as they hadn't called me back after several messages, and was told that there's some ridiculous backorder of more than 600 logic boards in Australia for faulty iMac G5's and that they couldn't give me a time estimate on how long it would take to get repaired.

Now I'm pretty angry.

I'm relying on this machine for work (like many other people) and they can't even give me a time estimate that I can work around. They also told me that the logic board would be replaced with a 'refurbished' Rev.A board, much to my disgust.

I've been reading a lot of blogs and articles tonight, and this is a real worldwide problem - literally thousands of iMac Rev. A buyers have had their logic boards/capacitors pop after about 6 months, and many of them have had to wait up to a month or even longer for the boards to arrive at their respective repairers. Many of them have then had the boards melt down again, or the power supply blow up and have had to return their iMacs yet again! One guy mentioned that since October, he's been without his iMac for around 3 months!!

I don't know - I'm just absolutely appalled at the lousy service by Apple Customer Care and total lack of responsibility by Apple to admit that this is a global problem and that they need to look into a worldwide recall of these crappy machines. I've been a Mac user for ten years, and I'm just horrified by events of late (not limited to this issue either).

I've written a letter to the manager of Apple Customer Relations here in Sydney, and I suggest that anyone else having similar problems to do the same.

22nd June 2005, 11:20 PM
I should also mention that, after a bit of investigating tonight, I've uncovered the following potential problems with the Rev.A. iMac G5's:

- Logic Board
- Capacitors
- Video Card
- Power Supply
- Screen (dead pixels and screen burn)
- Stuck DVD's
- Overheating
- Noisy Fans

Hope this helps anyone having these problems - call Apple and demand a replacement machine.

23rd June 2005, 07:56 AM
By Rev.A, I mean any Rev.A, new age Mac. Because it seems that in recent years the quality of Apple's machines have come down severly, but this is expected, since they are also much more affordable then ever before.

Also something to think about, to all those hoping for a Rev.B Board. I doubt you'll get it. My G3 iBook kept getting the same logic board. In fact, when you think about it, they could have replaced the entire machine after the second logic board, and most likely have not lost a dramatic amount of money.

Anyway, I digress, that isn't the topic of this thread. HIJACK!!! :ph34r:

With Apple, you will always get Like-for-like. None of us get special treatment. Don't set yourself up for disappointment.

danno, that's a fairly poor list of parts to go wrong. I mean, that's pretty bad. You'd expect to see one or two things on that list, but you're almost looking at the entire computer.

pipsqeek :thumbup:

26th June 2005, 08:58 PM
Hi Pipsqueek,

Absolutely - I agree - by the way, just read your post with regards to all the trouble you had with your iBook - kudos my friend - you are an inspiration indeed!

I can't believe all the trouble you had to go through - just unbelievable - if I had been a member of this site when you needed that powerbook, I would have definitely lent you mine :o)

With regards to the logic board and replacement machine - I've just found out that it's illegal for Apple not to offer a replacement machine when asked to, as long as your existing machine is seriously faulty. They just try to bully you into having it repaired time and time again - this is just sooooo wrong and you can seriously get stuck into them for this. And in your case, they should have replaced your machine at least with a like for like model straight away.

I've emailed Apple a second letter, letting them know I'll be contacting Consumer Affairs if I don't receive a reply to my first letter. I'm going in very hard on this one, as I don't want to have to go through all the crap of having logic board after logic board replaced on this machine. According to the AppleCentre, Apple are only replacing my stuffed Rev.A logic board with a 'refurbished' logic board, which I think is not good enough. I, like yourself, simply cannot afford to be going through this again when I'm running a business from home. It's cost me hundreds of dollars already in lost work (can't work on large graphic files) and I need a machine that I can rely on. This is what I thought I was buying when I shelled out $2499 in late January. This is not what I received. That's my premise for complaint at this stage. Simple as that.

Hope your iBook's still treating you well Pipsqueek - keep up the good work and let us all know if you have any more battles with Crapple - errr, I mean Apple.


1st July 2005, 11:54 PM
Update on iMac G5 Logic Board Replacement...

Just got my iMac back tonight - that's nearly two weeks without the machine. Apple took that whole time to get Applecentre the logic board, which arrived this morning - and kudos to the AppleCentre who were actually very helpful and had it installed within 2 hours of receiving it, even though they were really busy! I've got to admit, they were really helpful and very obliging!

I complained to Apple about the iMac and they agreed to extend my warranty for 6 months longer than it's original one year warranty, so that's better than nothing I guess - although I was planning on purchasing the two year plan anyway, so it's really not much good to me, but I must admit that, although it took two letters to get them to answer me, the lady I ended up dealing with was very nice and rather accommodating, so I must admit I feel a whole lot better about Apple Customer Relations now.

So, some good news finally - I hope I haven't jinxed myself - the iMac seems to be running okay, but only got it back tonight, so will keep the fingers crossed. I popped the back off to reinstall my 512MB RAM stick, and checked out the new logic board - can't tell whether it's a Rev B board, but where its' serial number is printed, it says something like "iMac G5 1.8GHz Better...blah blah" - not sure what 'better' is technically supposed to mean, except for the obvious - which almost seems too obvious if you know what I mean :)

The new logic board looks completely different to the old one - the tops of the capacitors now have a 'K' shaped cross through them, rather than the old 'X' shape, and the colour of the board is now dark blue rather than dark green... hmmm... things are in different places too. Can anyone tell me anything about this that might be in the know?

2nd July 2005, 12:24 AM
As you might already be aware, many people believe the capacitors marked with an 'X' were the ones prone to leaking and failure. The parts marked 'K' are supposedly more reliable. I think I read this on MacFixit, but I can't be sure.

It means that your replacement board is from a later run of logic boards, which ought to have a lower rate of failure than the early ones.

2nd July 2005, 12:25 AM
check your graphics card under the system profiler
if it's a radeon 9600, then you have a rev b.
geforce 5200...it's a rev a

2nd July 2005, 11:10 AM
Thanks for the information guys - I did a bit of research myself last night, and it seems that, indeed, the 'X' capacitors on the earlier Rev A boards have had about a one in three failure rate - the company that make the caps (Nichicon) are usually very good, but they must have had a bad batch of capacitor electrolyte - which has apparently been a problem since about 1999, when some shady company stole a capacitor electrolyte formulae from another company, only the formulae hadn't been finished and was still faulty - since then, it's been hit or miss for capacitors in both the PC and Mac worlds. Nichicon are generally a reputable company and are highly recommended by electricians for capacitors, and it seems that in this case, it wasn't really their fault - they just received shotty components themselves.

My new capacitors on the replacement logic board are marked with a 'K' and are made by Rubycon - these are also highly recommended and apparently these have been less prone to bulging and leaking - we'll see how we go.

Anyhoo, I've posted a pic of the old and new caps for you all to check out...

3rd July 2005, 07:59 PM

I have experienced the capcitors leaking and burning my midplane beyond repair.

I am taking it to my local apple repairer tomorrow as I couldn't get it there on friday after it happened.

I have been told they will be able to replace it straight away with a new one. This I am not really counting on after reading some of the other posts.

But only time will tell.


3rd July 2005, 09:04 PM
just a question for those who have had burst capacitors...how far up do the capacitors bubble?

4th July 2005, 08:23 PM

The capacitor electrolyte (the brown goo) can leak out about 1-2mm by the time your machine bites the dust. It's caused by dodgy fluid that heats up so much it boils inside the capacitor, pops the top and leaks out.

Check out the pics on my post a couple of replies up from yours...

8th July 2005, 03:37 PM
My G5 iMac died last Saturday just after I sold my only other Mac (G4 Cube). I searched the net, found out the MB was dead (leaking capasitors) and so I dropped it in to the service centre on Monday. I was told if they needed to order a part that it would be ready Wednesday or Thursday at the latest. I called them yesterday and was told that there were no stocks of the part in Australia and that it had been back-ordered, seems like I'm not alone. I asked if that is so how long would it be cos I needed it for work and if it were to be more than a week I would need to find a replacement. They told me they would try to find out but could not make any promises. It is now Friday afternoon and I am still waiting for a reply. Not good enough!!

8th July 2005, 04:40 PM
No, it isn't good enough, is it?

Btw, the current (replacement) iBook I have has been going okay.


9th July 2005, 01:50 PM
I am another very dissatisfy customer with Apple. Especially on this display problem regarding iMac G5, and the way they treat customer as a liability, when its them, who had serious problem with the quality assurance procedure.

I am wishing to collect your Case Number when you file your machine with Applecare. I am treating this case number as a vote of no confident, also to support my further action to seek third parties assistance.
Please send your case number to the following email address if you had problem with the midplane or logic board.


Why am I doing this? Simply because this is obviously a known problem worldwide, and Apple is not willing to admit the scale of the problem. They rather choose to ignore it. What about those customer who rely on this machine to make a living? Well, their ignorance simply means "you valuable customer should buy another one of our product for our mistakes on our quality assurance failure". This is completely outrageous and unacceptable.

Today, when I asked them if they can fix my machine with Rev.B logic board or a replacement machine, they simply rejected me. They said those discussion in the web are only isolated cases, and there aren't great deal of problem for recall. In order to prove that they are wrong, I am asking you to send me the case number as a vote of no confident.
With your votes, I will take them to the local consumer authority and some other public organisation for assistance. I don't want to say exactly at this point where these votes will go, since Apple's guy may be watching. But I will assure you that I will do my best to take them to good use and I will keep you posted.

Please spread the word as I wish to gather as much momentum as possible. I really wish Apple will take this logic board capcitor problem seriously, instead of wasting our customer's valuable money and time. Apple is a good company with good reputation in the past, I hope they don't leave the problem as it is and resulting a crappy reputation like that of other monopolies.

Here are a few URL that you may find information about this midplane / logic board / fuzzy display problem:

Capacitor Plague??

Quote from this page:

As the capacitor ages, its capacitance decreases while its effective series resistance (ESR) increases. When this happens, the capacitors no longer adequately serve their purpose of filtering the voltages on the motherboard, and system instability results. Some common symptoms are:

* Not turning on all the time; having to hit reset or try turning the computer on again
* Instability (hangs, BSODs, kernel panics, etc), especially ones which get progressively worse with time
* Vcore or other system voltages fluctuating or going out of range, possibly with an increase in CPU temperature as the core voltage rises
* Memory errors, especially ones that get more frequent with time
* Spontaneously rebooting
* Failing to complete the POST, or rebooting before it is completed
* Never starting the POST; fans spin but the system appears dead

Bloated iMac G5 Capacitors

What will you sees if you have this problem 1

What will you sees if you have this problem 2

Photos on how to install midplane

Why these capacitor failed?

discussion 1

discussion 2

discussion 3

11th July 2005, 11:04 AM

I just got a call from my Local service centre (Apple) about my iMac G5 which is already been fixed and awaiting me to collect it. It has only taken four days which is rather quick compared to others that have had the same problems.

I will post again when I get it home and let you all know who it is.


11th July 2005, 12:20 PM
It's now a week since I dropped off my faulty iMac and they still won't/can't tell me when they will get the part in. They hadn't got back to me and so I popped into the shop this morning. They said they still don't know when they will get the part cos Apple head office had not replied to their email that they sent on Friday morning. How long does it take to see if stocks are on the way or not. I said I'm not expecting them to find me a replacement but if it's going to be more than another week I can get another cube to carry me over until my iMac is fixed. What I don't want is to go through the processes of getting one, installing everything only to have them call me the next day and tell me my iMac is ready to be picked up. Macs are more often used by professionals, why can't they run their supply line more professionally.

14th July 2005, 06:39 AM
Hi, I dropped my iMac in for repair last Saturday. Next Byte have confirmed that the problem is with the logic board. A new part has been ordered and should be in stock on Friday, giving me a turnaround time of one week which I can live with.


14th July 2005, 09:34 AM
Jazzap, They had told me when I dropped mine off on the Monday that if they needed to order in a part, I would get it back Wed or Thurs at the latest. I asked, "you mean if you don't need to order in a part?" Which they replied, "No, if we need to order in a part." I've been into the shop now 3 times to try to find out how long I will need to wait, I then tried phoning and am still waiting for a reply and so yesterday I sent them an email. They finally replied to my email and this is what they said, "We do not have an ETA for your iMac's new logic board. Apple's Global Service Exchange system shows an expected ship date of 11/07/2005, which would imply that the part should be here today/tomorrow. However, an enquiry against availability of that particular part indicates that they are still not in stock. Apple's Service Admin team have told us that the part has not shipped; at the moment they do not have an ETA." Let me know if you get it in the week.

15th July 2005, 07:01 AM
Grei - you've shattered my illusions of a quick turnaround! I'll post tonight on whether it arrived or not.


15th July 2005, 02:58 PM
The new logic board has not arrived today as predicted by Grei. I was told by Next Byte that Apple is giving out these crazy etas for parts and then failing to meet them which is leaving Next Byte to deal with some pretty pissed off customers. More news when I get it.

17th July 2005, 10:13 AM
I called the shop that has my iMac on Friday afternoon and they checked with Apple who have now said they have ordered the MBs but have no ETA or even when they will leave the factory. It's looking like a long wait and so I have gone out and bought a cube to get me by. Apple continue to say this is an rare case and therefore they have no stock, the shop have said they haven't had any other cases and they have sold 100s. I think they have been told to say that by apple because one of the girls at the shop who usually talks a lot seems to be trying her hardest to say nothing. I'd love to know how the true number of cases there are out there. I've had Macs since my SE back in 87 and although I now also have a PC, I remain loyal to Mac and alway have the latest for my accounts and important stuff. It's shocking Apple can do this to their loyal customers.

17th July 2005, 07:46 PM
I have my iMac 20" (Rev A - I Guess due to the problems with it) in the repair shop (Design Wyse)

iMac has been in for 1 service already because of a white flare on the bottom LHS of the screen. They replaced the display. I understand this issue is quite common.

Got the iMac back, sure as sh*t the same white flare problem appeared a second time after 2 months. So I returned it for service again... but It's been 4 weeks so far. The logic board has been replaced, just waiting on another new screen to be delived by Apple. Hoping this week maybe.

After all the stuffing around, I'm basically going to have a brand new mac when I get the damn thing back.

I understand form the service team that if the iMac fails again, I will get a new one.
I'm tipping/hoping that the iMac will fail again.

Wondering if I can pay a little extra money and upgrade from the 1.8 to the 2.0 Rev B?

For all the inconvenience and hassle I think Apple should just upgrade me to the latest iMac 20" 2.0mhz Rev B model and I'll be a happy customer.

Looking back, the iMac has spent more time in the repair shop than in my posession.


20th July 2005, 05:52 PM
Had a call from Next Byte this afternoon. The iMac has been fixed and I will collect it before the weekend. More news when I&#39;ve spoken to Next Byte.

Grei, you got yours back yet?

21st July 2005, 07:32 AM
I just got back my iMac, I guess 2.5 week isn&#39;t that bad. I haven&#39;t looked at the board but the specs are the same graphics, speed etc. Hopefully, it will be a newer run or the Rev A and won&#39;t have the problem again. The main problem is after 2 weeks waiting and them not being able to tell me how long it was going to be, I went out and got a cube, I&#39;d like to keep it as a backup but the wife doesn&#39;t want another computer laying around. Jazzap, how is yours?

21st July 2005, 07:04 PM
Seems fine thanks. Have moved house today and haven&#39;t had chance to check it out properly yet. Hope to have a chance to do so over the weekend.

Good luck with the Mrs&#33;

21st July 2005, 08:24 PM
I left my iMac G5 in to be repaired 5 weeks ago. Was informed only this week that the logic board had to be replaced after waiting 3 weeks to arrive from Apple. Turns out the logic board replacement hasn&#39;t solved the problem and now the display needs to be replaced, which means another 4 or 5 week wait to order it from Apple. This iMac has already had the midplane replaced 3 months ago. In total my 7 month old iMac has spent almost 3 months in for repair. I rang Apple yesterday and told them I want either a new iMac or a full refund, and I will refuse to accept my computer. They&#39;re looking into it for me. I will keep you posted.

P.S. My PC loving housemate is pointing and laughing at me now. Shouting that Apple products are shit. Right now I&#39;m inclined to agree.

22nd July 2005, 12:30 AM
PCs are not the answer, my friend&#39;s Dell has been out of action for a long time. The problem is when you buy a computer as a complete unit, if anything goes wrong the whole thing is out of action. I have built my PC from components, of course things still die, the factories that put these things out make hundreds an hour. I&#39;ve had bad HDDs, Floppies, DVDs and motherboards but when they die, your whole computer isn&#39;t out of action, you just replace the bad component and put in a claim for the faulty part. Even if it&#39;s a motherboard you only lose the use of you computer for a few hours.