My MacBook started acting up, getting really slow reading and writing things. Started to fail, sometimes could not boot up sometimes could. Figured it was the hard drive and backed up everything just in case. Now the MacBook will not boot up at all. I have a new SSD coming from Amazon tomorrow. I borrowed a hard drive reader and took the drive out of my MacBook and plugged the USB into a friend's MacBook. It read everything and all the data is there. Is there a chance this is not a hard drive problem?