macbook pro won't boot up

[cooperplace]

I've got a A1286 Macbook pro, about 7 yrs old now, that won't boot up. The apple symbol comes up and then either the progress bar stalls forever about 1/3 way thru, or it goes to a white screen of death.

It's got a nearly new 500gb SSHD which I've removed and tested, and re-installed, it's fine. I can start it in target mode and read its drive just fine using a cable to another mac, so I doubt that the cable to the SSHD (a known issue with these) is the issue.

None of the startup options (safe, etc) yield anything other than the above description except verbose, which gives a couple of pages of text on the screen then it stalls forever, with the last line of text being: promiscuous mode enable succeeded.

The OS is whatever comes with these + updates. I don't think it's an OS issue: it doesn't get that far.

But the other thing that's weird is that if I try to reload the OS from the install disk, it gets as far as asking what disk to install the OS on, BUT IT CAN'T SEE THE SSHD.

I have no idea of how to even troubleshoot this thing. Any suggestions would be appreciated.

 

[chscag]

Are you able to boot the machine with the original disk and with the SSD removed?

 

[ferrarr]

Is it ann SSD or SSHD? It does sound like part of it is dead? When it was connected in Target Disk Mode, were you able to see and open files on the drive?

 

[cooperplace]

the SSHD is fine: in target disk mode its files can be opened and read. With the SSHD removed and the original startup disk installed, it goes straight to the white screen of death.
I'm thinking logic board.