Can Logic Boards be Repaired?

Not really unless you take it to some body that can diagnose the exact problem, isolate the failed part, obtain a new working part, remove the bad part then install the new working part. That is a lot of ifs.

As far as I know not even apple fixes logic boards. They just replace them with a new board.

I don't remember any logic board problem which caused Mac OS X to start in safe mode, but I suspect about PRAM > http://support.apple.com/kb/HT1379 Note that I'm not sure. I suspect about the PRAM because it stores boot parameters.

Apple doesn't repair logic boards. I have seen here that some technical services repair logic boards, but I don't trust fully in them

Yes they may but apple never releases that info to the general public. Even if they find a flaw rarely do they issue a recall on the whole system.

Creteway wrote:

Or are they not the sort of company that investigates why their products are failing?

To contact apple all you have to do is dial 1-800-myapple. I didn't realize aliens had a shorter or easier to dial 800 #.

Bring it to an independent AASP who will run the Apple Service Diagnostic and might be able to pinpoint the exact component failure on the board. Since it's only booting in Safe Mode, it's possible it's the GPU, which isn't easily replaced, if at all. And you'll probably end up spending just as much for a component replacement as you would for a new board. But I have no way of being certain of that, so you might want to look into it.

I don't see why a new board would necessarily fail just like the old one. But one common cause of hardware failure of any kind is long term "sub-lethal" overheating. There are ways to try to avoid that. Post back if you want to know more.

Almost every Mac Apple sells would fall into the category of "defective," since there isn't a Mac of any kind, or any computer brand for that matter, that hasn't failed for one reason or another for someone. True, some models and some components are perhaps more failure prone than others.

I understand your disappointment, but going on about this serves no purpose now.

The logic board is a printed circuit board with hundreds capacitors resistors and similar small components soldered onto the fine copper strip.

Additionally there are sockets for RAM drives and CPUs, GPUs etc...

One of the common issues with PCBs in general is solder bleed shorting as a result of heat build up- If this happens its terminal !

Apple have diagnostics that can identify a fault and provide a reference number however frankly if the fault IS on the board (broken copper strip solder bleed or tiny resister for instant) its remains easier and more cost effective to replace the board than attempt to strip the board out - bench test find fault replace and reassemble.

Replacing PCBs is industry practice.

Those fault diagnostic results ARE analyzed by Apple for trends and to identify quality issues.

Lowluster is quite wrong in saying that Apple are secretive if there is an identified design or engineering issue.

In fact there have been such problems in their products and they HAVE had programs to replace those FREE and after normal warranties such as a problem with iBook logic boards faulty MacPro graphic cards,Macbook damaged bottom panels and battery swelling are some.

Replacement

http://www.dvwarehouse.com/iMac-Intel-Early---Late-2009-Logic-Board-c-5483.html

And

http://www.macservice.com/imac.html

Just Google imac logic board repair or replace

Ah yes...sorry, didn't realize your location.