Upgraded to El Capitan but it keeps crashing & rebooting
So recently I upgraded my Macbook Pro from 10.6.8 Snow Leopard to 10.11.6 El Capitan. It seemed to run smoothly enough, but after several minutes of usage it would always freeze and reboot.
I tried a clean install of 10.11; same thing. I tried clean-installing it on another brand-new external hard drive I had laying around; same thing. I tried running it in Safe Mode; same thing. I tried unplugging all peripherals (USB mouse, speakers, etc.); same thing. I tried a memtest in Safe Mode, but the test reported no errors. My Mac model should be compatible with this OS, so I am at a loss concerning what this may be.
Some more info about the Mac:
- Mid-2007 15” Macbook Pro; A1226 model 3,1
- 2.4 Ghz Intel Core 2 Duo T7700 processor
- NVIDIA GeForce 8600 GT 128 MB graphics chip
- 4GB of RAM (from Other World Computing - only using one RAM slot since the other one doesn’t work)
- 500GB Mercury Electra 6G SSD (from Other World Computing - only a few months old)
- Also has third-party mag-safe adaptor (OWC) and third-party battery, though I’m not sure if those would affect anything.
I’ve taken immaculate care of this laptop and Snow Leopard always runs flawlessly. Any ideas on what might be causing the crashes? Is my Mac just not compatible with the El Capitan?