Symptoms of a bad ribbon cable for internal hard drive MB Pro

I fixed my problem and wanted to post what I found. My MB Pro 13 (2009) restarted by itself the other day and then came the blank gray screen, no boot. I reseated the ribbon cable connector on the board and it rebooted okay and worked for a couple hours and then quit again. I plugged in the external drive for Time machine which is bootable but the computer would not see it unless I held the Option key. Once I did this it saw the drive and booted fine. I inspected the cable because I saw some vids that showed the aluminum case of the MB would wear into the cable and cause problems. My cable looked fine with no visual defects. I figured it was time to upgrade to a SSD so I bought one and plugged it in. The MB did see the drive but could not format it. I kept getting a "Disk Erase failed unable to write to the last block of the device" At this point I read more about bad ribbon cables on this model MB so I bought one. Sure enough the cable was bad. It's been a week now and my MB is fine, actually faster now with the SSD. It is very easy to replace the cable and hard drive as long as you have the tiny screw driver.

I hope this helps someone in the future. If you don't have an SSD I highly recommend getting one along with a new ribbon cable. The cable is cheap!