Disks won't spin in 1050 drive

[+DamonicFury]

I recently acquire a 2nd 1050 disk drive from Ebay (along with a 800XL), but it seems unable to spin a disk. The belt is unbroken. I initially suspected the motor, but unplugged it and plugged it into a working 1050 and it spun just fine. But it still didn't spin when placed back in the Ebay 1050. Any ideas of what else in the 1050 might cause the drive motor not to spin?

 

Or alternately, is anyone looking to buy a broken 1050 or some of it's parts? :-)

[ApolloBoy]

If I'm right, I think there's a track sensor or something that might be dead.

[Shawn Jefferson]

I think if the Track zero sensor is shot, you should hear the head banging up against the stop and it continually tries to seek track 0. If it doesn't spin at all, you might look at power, and specifically those big caps at the back of the drive (?)

[+DamonicFury]

The head itself seems to move just fine, so it doesn't sound like a sensor problem. Any specific tips for testing those three big caps? (I do have some electronic knowledge, but it's a bit rusty!)