Dead iMac after SSD install

I upgraded my MacBook Pro and iMac to max out the memory and install SSDs in each. The memory upgrade was easy, and went without a hitch. Likewise, the SSD (Crucial M4 512GB) worked like a charm in the MBP, though I have yet to address Bootcamp, Parallels, and my Windows installation.

The iMac, not so much. Following all of the available online guidance, I was still rewarded with a stylish boat anchor. The iMac will not power up at all: no clicks, whirrs, buzzes, anything. I've rechecked connections, and even tried the original hard drive configuration. I've tried different power outlets, resetting the SMU, removing and reinstalling the RAM, all to no avail.

I suspect the power supply, but do any Mac gurus know of anything else I might be missing? I can't find a fuse anywhere. It's a late-2008, 20" model, 2.66 GHz Core 2 Duo, model A1224, MB342LL/A, 6GB RAM.

BTW, does anyone know if there is any sort of safety interlock that keeps the machine from powering up unless the case is completely reinstalled?

Thanks!

BTW, does anyone know if there is any sort of safety interlock that keeps the machine from powering up unless the case is completely reinstalled?

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No power interlock that I know of. But it does sound like the PS in the iMac may have coincidentally failed when you installed the SSD. Do you have a VOM handy? If you do, you might want to check some voltages. Go to the ifixit web site and look up the take apart instructions and instructions for changing out the PS for your 2008 model iMac.

iFixit: The free repair manual

chscag said:

Go to the ifixit web site and look up the take apart instructions and instructions for changing out the PS for your 2008 model iMac.

iFixit: The free repair manual

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Thanks, I'll check it out.

Say, is that an A-26 in your avatar? Cool machine.

Say, is that an A-26 in your avatar? Cool machine.

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Thanks for noticing. It's a Douglas B-26C "Invader" that I was once a crew chief for back in my old military days.

chscag said:

Thanks for noticing. It's a Douglas B-26C "Invader" that I was once a crew chief for back in my old military days.

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Very cool...love the warbirds.

I was successful in installing the new power supply. I was confronted with a new problem: the machine would boot up and then quickly shut itself down. I suspected that it thought it was overheating, as the fan was running wide-open. I had removed some screws around the logic board and heat sink in order to get a little more slack in the SATA cable.

I had to leave town for a few days, and so had difficulty in remembering which screws went where when I came back. I had even left a couple out since they didn't seem to fit. I reviewed the info on ifixit, and carefully reinstalled all of the screws in their proper locations et, voila. Works like a champ now. My first clue that things were going to be better was the reduced RPM of the CPU fan. So, word to the wise: don't remove any more screws than you have to when it comes to the logic board, and pay careful attention to getting the right screws back in the right places. There are subtle differences in the thread coarseness, length, and diameter, and the differences do matter.

Also, be very careful around the single power supply temp sensor wire. I was trying to pull out the main power supply connector, and clumsily pulled out the other wire as well, damaging the connector in the process. Thankfully, I was able to fix that without too much trouble.

So, I now have a Crucial M4 512Gb SSD now living happily in my 2008 iMac.