I was happily shredding some documents the other day when suddenly my Fellowes POWERSHRED 420HS ground to a halt. This DOD approved high-security shredder has been serving me well for almost a decade:
It creates indecipherable chaff (shred baby food):
Peeking inside, there’s not much to it:
Hand-turning the drive motor didn’t budge the shredding gears, so I had to pull the 49.25 pound (22.4 kilo) mechanism out for cleaning and diagnostics. All the retaining bolts are underneath the mounting platform:
After peering into the gearbox (right side), and having no luck getting the shredder teeth to turn, I popped the retainers & bolts off the other end to loosen the gears and applied generous lubrication. At that point I was able to hand-turn the motor fan and got the shredder teeth to move a bit in each direction. Adding more oil (I noticed some corrosion), and after more wiggling back and forth, I was finally able to get the teeth to break free and rotate smoothly. Upon close inspection, I noticed three teeth that had been chipped:
I’m still not sure why the unit jammed, but after cleaning & lubricating, it’s back to its old self. When I re-installed the unit, it wouldn’t stay running; I found a hall-effect sensor used to sense gear rotation had been nudged slightly off-kilter:
Moving the transistor-like device on the board just a bit fixed the problem.