ProFile won't spin when connected to controller board

[MacinPosh]

I recently acquired a 5MB ProFile drive in an unknown condition for use with my Lisa.  

I promptly replaced the power supply caps in hope that the drive would be operational.

Powering the system on resulted in a high pitched whine but nothing else, but when I disconnected the internal data cable between the controller board and the hard drive, it did begin to spin up.

Any suggestions on what to try next? I've tried reseating all the chips. Are any particularly prone to failing?

Is there any way to narrow down whether the controller board or the drive analog board is at fault?

 

 

[MacinPosh]

Following up on this after a long time. 

 

After a lot of head scratching and component swapping, I went back to basics and discovered that the problem was in fact with two capacitors on the Hard Drive's analog board that had gone short circuit. (Shown in the RED box in the photos, compared to the original in the GREEN box)

After replacing them, the drive span up and "promptly" booted to MacWorks. 

 

I learnt the typical lesson of check for the common simple issues first!

 

 

[MOS8_030]

Great job finding and fixing the problem!

Once again, caps are the weakest links in these old devices.

[olePigeon]

Woo, nice.  Always great when it's a cheap fix.

 

I recently bought a Joust arcade that "doesn't turn on."  Turned out the trim pot on the analog board was shot.  The arcade worked fine.  It's also fortunate because the machine remained unused for many, many years.  So no screen burn in.  Nice and crisp.