mobile wrote:
hello,
I have a few HDs that don't seem to power up. I see where people on this
board are swapping out controller boards, and chips on the board.

at the risk of sounding like the village idiot, how are you troubleshooting
the bad boards or the drive in general. do I need a multitude of $$$$ test
equipment or ? any help would be appreciated.

thanks



By "Not powering up" do you mean not spinning? If the drive is not
spinning with just power applied it could be two things assuming that
power is reaching the HD. First old drives sometimes fail to start due
to the heads sticking to the disks. Tapping the drive against the palm
of your hand while power is applied will sometimes free them. It is a
temporary fix however and the data should be copied if it is needed.

The second most likely fault is a bad logic board. Although it is
possible that the motor is faulty, it is rare. Swapping out a logic
board is a fix for a faulty board, but you need to find one just like
the old one. Sometimes it requires the same ROM series rather than just
the model number of the HD. For what it is worth, many times the fault
on the PWBs are open chokes. If you find one it is easy to replace it
with one from a scrap PWB.

As for test equipment, I would think that a good DVM would be the only
tool required for trouble shooting the PWBs. It is alway nice to have
more equipment, but since many ICs are custom made, it is highly
unlikely that a replacement is readily available. At least that has
been my experience.