MacBook Pro intermittently won't start with fan running strongly
Running Apple Hardware Test turns up error message 4HDD/11/40000000:SATA(0,0)
SATA cable (on your advice) and hard drive were replaced (with SSD) recently. Running Sierra.
After running the AHT (associated with the fan running strongly and the strip behind the keyboard being hot) the computer then boots ok. This appeared to fix things once before, the other time I have no idea why it resumed working normally.
When the device is down it will not run Disk Utility or safe boot. Running fsck did not help. Resetting NVRAM no help.
Your assistance would again be much appreciated