Logic board replacement for early 2008 24" iMac

[Mike Toole]

Hi folks,

I'm not new to macs, but I haven't used one much in recent years. But this week, the trash fairy saw fit to allow me to stumble across a 24" iMac in a dumpster! I couldn't believe my luck. Sure, SOMEthing had to be wrong with it, but cosmetically it looked OK!

Upon getting it home, I was further amazed when it booted up... once. Very, very slowly (about 15 minutes.) I had a busy weekend, then tried it again last night. Instead of the slow-boot, it now just restarts over and over again, usually before the startup chime can even sound. To me, this would seem to indicate a faulty logic board (that's what google tells me, anyway). I did the research and discovered that using Apple to get a replacement will cost many hundreds of dollars, so I'd rather buy an OEM or secondhand board myself and do the replacement. I routinely replace optical blocks in LCD projectors, so I'm not intimidated by cracking open the iMac and swapping in a new board.

I just have one question: what's the specific part # for the iMac 24" early 2008 (aluminum) logic board? I just want to make sure I don't mistakenly order up the wrong item from eBay.

I'd also like to solicit advice: has anyone else done this repair? How were your results? Are there steps to take that will prevent a similar breakdown (I understand this is pretty common in older imacs)?

Anyway, the rest of the machine appears fine, so I'm pretty excited. Not as good as a TOTALLY FREE iMac, but a $150-200 iMac, especially with that beautiful 24" display, seems like a good deal to me. I figure if the repair sticks and I get an SSD, I can get another 2-3 years out of this machine, easily. Hope y'all can help!

 

[Fairfax]

If you want to find out the specific model number for the logic board you will need to go under the hood and take a peak (it was like that for my old macbook pro). Here is what I saw at apple discussions,

"Your logic board will have it's own SN, separate from your computers's SN. Called the EEE or logic board number. The EEE number is the last 3 of the last 4 numbers/letters of the logic board SN, IE: e801513wefpua, the EEE number is fpu. That's what you want to look for. It will be on a barcode...."

If you carefully follow the repair guide at ifixit and take your time you should have no problem replacing the logic board.

 

[Brian33]

I just have one question: what's the specific part # for the iMac 24" early 2008 (aluminum) logic board? I just want to make sure I don't mistakenly order up the wrong item from eBay.

These images supposedly came from the Service Manual for the Early 2008 iMac (24"). According to them, you need:

661-4666 for the 2.8 GHz logic board and 661-4667 for the 3.06 GHz one.

I purchased the 2.8 GHz model in May 2008. It's my "daily user" machine and it's going great! I put in 6 GB RAM, replaced the original HDD with an SSD, replaced the optical drive with a 2.5" 1 TB HDD, and set up a DIY Fusion drive running 10.8.5. I'm very happy with it and hope to get another two or three years from it.

Hope you can revive your find!