EII Repeatedly Tries To Access Drives

[who]

Hi,

I got my EII back from the shop and it worked fine for weeks, then one day I come home and it was repeatedly trying to access both drives (HXC and 5.25).  When I say repeatedly, I mean many times a second.  (It was happening so fast that the LCD couldn't keep up.)

Any ideas what might be wrong?

who

[who]

So, I got an opportunity to open my EII and found the following:

1. The drives exhibit the same behavior even if the IDE cable is disconnected from both drives
2. one of the components on the power supply board is buzzing clicking at the same rate the drives are engaging.  (I couldn't hear it until I removed the top.)

[who]

Replaced the power supply, replaced the IDE cable and reseated all ICs and the problem seems to be gone.  (fingers crossed)

[modmaker]

I can confirm the same.
After some good use, the machine refused to boot one day and as you descibe, accesses the drive constantly.

I tried disconnecting the floppy cable (last time it happened a connector on the floppy cable was broken, probably shorting), but I got the same result.
Then I tested connecting the HxC to an external powersupply (an older Dell Optiplex on the side (but not as old as the EII    )) and the machine boots fine and stays stable.

At 5+ I had:
Dellpowered: 5,10v
EII-powered: 4,46v

HxC doesn't use 12 volt, so, it sounding like a small machinegun, was related to being fed too low voltage on 5+.
Fixed, and back in business.   

Like our good Dr.C says: These machines are choosy on what power they are fed.