Mac Book Pro grey screen during startup

Mac Book Pro

Problem: When we try to load normally, we grey screen. The grey screen happens after the small apple symbol and round spinning circle. The fan was running more than usual when the problem originally started.

Interestingly enough, we can load the computer in Safe Mode.

Troubleshooting:

1. We reset the NVRAM
2. We attempted to load the computer in Internet Recovery mode. This loaded, but then resulted in a grey screen when we tried to get to the Disk repair & verify option.
3. We do not have the installation discs.

Any additional troubleshooting steps that can be performed in safe mode would be appreciated. The computer is about 3 years old and is out of warranty.

Thank you for your help.