Whenever I have an SSD (crucial mx100 or samsung 850) as my internal hard drive, my macbook has problems with sleep/wake. If I unplug (run on battery) my macbook and let it sleep, the SSD (or stock hard drive) does not wake up. It will work for about a second then it'll freeze for a few and quickly flash a white screen and reboot. This also happens when I close the laptop while it's plugged in and I try to reopen it. Sometimes it will happen randomly after a few hours of using the computer (and possibly letting it sleep in-between). Some solutions I tried: 1. Reseting SMC 2. Installing OS X via USB and installing it when it's my internal drive 3. Reinstalling OS X 4. Repairing the drive in disk utility Solutions that worked at first (for a few days), but eventually failed: 1. Replacing the hard drive cable. (No problems for about a month) 2. Preventing the drive from going to sleep in settings I can boot the SSD from a USB enclosure perfectly fine. When I have the SSD as my internal drive, I sometimes get the prohibitory sign at boot and the file system will appear corrupted. But the minute I put the SSD in a USB enclosure, everything works perfectly again (even after it appeared corrupt as my internal drive). SMART sometimes fails on my drive and other times it passes. I once booted up and heard beeps, HOWEVER, my ram sticks are good and I've tested them several times. What is going on? Anyone know? Also, I have high data error counts in DriveDx with the SSDs. The stock hard drive has a data error count of nearly zero. The stock hard drive also perfectly fine as my internal drive and has no problem with sleep or wake. UPDATE: After reinstalling the stock hard drive and having success for a day. I am now experiencing the same problem with the stock hard drive. How I can guarantee my macbook to crash: 1. Unplug it from charger 2. Let it go to sleep 3. Reopen it and it should crash within 2 hours Potentially related issue: My magsafe light is sometimes dim.