Why does a MacBook Pro 17 intermittently start up after SSD upgrade?

Hi all,

I’d much appreciate anyone’s help with a Macbook Pro 17” Mid-2009 (unibody) start-up issue please.

I replaced the Apple OEM laptop hard-drive with a new 250 GB SSD hard-drive from Crucial (MX 500), and now the MBP 17 will not respond to the power button most of the time. Only very occasionally will it start up and I can’t see any logical steps leading to this.

First I installed Mac OSX (Snow Leopard 10.6.8) from the OEM CDs, but the intermittent start-up problem continued. Then I upgraded to El Capitan (the latest OS version compatible) but the startup problem persisted.

I’ve tried resetting the PRAM and SMC and starting in safe-mode, but these haven’t made any difference. The SSD is GUID-partitioned and HFS Journal formatted. The latest compatible firmware has been installed. The hard-drive cable isn’t damaged.

The only thing that I’ve found can make a difference is unplugging the internal battery and the SSD drive, then reconnecting them a short while later. *Sometimes* this seems to be enough to ‘reset’ the system and then it powers up as usual. But most of the time, this isn’t enough so the computer remains dead and won’t power up. (I’ve tried this step with the power adaptor plugged in and without.)

Any advice to get this resolved would be very much appreciated! Thank you! :-)

Crucial SSD drive: https://uk.crucial.com/gbr/en/macbook-pr...