Hello, thought perhaps writing out my current issues with an older MacBook Pro might help to figure out what happened and where to go from here. SUMMARY: SSD replacement leads to apparent mobo failure; no apparent mechanism for mobo failure in chain of events The hardware: http://www.everymac.com/systems/app...-2.8-aluminum-15-late-2008-unibody-specs.html I had long ago maxed out the RAM and bumped the HD to 1gb. At the time of these events I was running Yosemite. I sourced and installed a TOSHIBA-TR150 960gb SSD marketed under the brand OCZ Trion. After cloning the drive using SuperDuper and swapping the new drive in, the machine booted but then would randomly shutdown. I tried a clean install and migration (no dice) and corresponded with Shirt Pocket all the way through, as they were interested to understand why the cloning might not have worked. Some legwork uncovered the unfortunate fact that the SSD was not supported by the manufacturer in this model MPB due to the use of a buggy SATA controller in Apple's build. http://blogs.helsinki.fi/tuylaant/2014/01/upgrading-old-macs-to-ssds/ https://support.ocz.com/customer/en...d-nvidia-chipset-based-macs-and-motherboards- So I repurposed the drive in another machine, a more contemporary Mac Pro tower, and did a bit more research before buying another drive, which I formally verified (on the phone!) with the manufacturer as supported before purchasing, the Crucial BX200 960GB. It was not going to support full SATA 3.x transfer speeds but hey, the manufacturer stated it would work. So, this time, I went straight for a clean install and migration, and the machine booted up and ran well for about a day. Then it shut down without warning at the end of a workday and rebooted into the recovery partition. I decided I didn't have time to work on it more right then and shut the machine down from the recovery boot, intending to reboot into recovery the next evening. During the next 24h I also decided to punt and ordered a 1gb SSD from OWC instead of trying to save that $100 on the assumption that the Crucial drive was also going to prove unrecoverable. Either way it would save a day and I could always return it if I was able to get the Crucial working reliably. However, things took a turn for the unexpected. The machine was solidly unresponsive to the power button. The battery charge indicator light showed full and the power adapter illuminated green when plugged in, but there was zero response to the button, no clicks or fan whir or chimes or any indication that power was flowing to the device to start it up. It seemed odd, but I just hooked up the recently swapped-out HD and tried to reboot in from the external. Surprising me, but unsurprisingly if boot power was not available, the external device dd not make a difference. I swapped the original drive back in. No dice. I punted again and just ordered a new (used) MPB with similar specs, somewhat newer, off ebay, so I would be able to continue work on the upcoming gig I had intended to upgrade the drive for. I took the dead MPB into the Apple Store thinking they might be able to run a diagnostic but essentially they told me that their TOS prevent them from even opening the case on an older product and that I would be better off finding an indie shop. By now, my hypothesis was that in my repeated drive swapping on the laptop, I had zapped the motherboard - something I now doubt. By my count, I had swapped a drive into the HD bay at least six times in about three days up to the point that the machine rebooted into recovery mode. After I pulled the second SSD, I put the original drive back in. That original drive had been multiply verified as bootable by using it externally on two other systems in the house specifically to check its boot validity. So here's why I think the mobo hypothesis is incorrect. The device failed to boot off the internal primary partition and failed over to the recovery partition before being shut down in an orderly fashion. The device had not been opened since the Crucial drive was installed, and that drive had been engaged as the primary boot volume at least three times prior to the volume failure, with the MPB either boot cycling or entering a fully shut down state. So I think it's quite unlikely that I somehow introduced static electricity into the motherboard in such a manner that it would manifest only after a couple of boot cycles. The hardware-oriented course of action here is to take off the case and try to jumper the mobo. But I have a hunch that there is something I'm missing in my bouts of troubleshooting and wanted to lay it out here and ask for input. First, does anyone have links to a similar story, where a new HD or SSD appears to kill boot power? Second, is there a more detailed series of boot-power troubleshooting steps than these posted at iFixit? Their steps clearly point to the mobo. https://www.ifixit.com/Wiki/MacBook_Troubleshooting Anyway, thanks for your thoughts.