Hi,
it could be also a bad accumulator !
Check also your PSU, maybe it gets too old and can"t output enought (i had this problem on my 1230).
For your old HDD, i had a similar problem in February with a Quantum SCSI2. I put it on a hot surface (very hot towell, don't put it directly on a radiator !!), and plug it for 45min/1h, it should come back to life.
