Fellowes P400C shredder

Look at the manual in the link below. If you do not find the answer, call Fellowes.

Fellowes Shredder Manuals

It sounds as if the SafeSense is improperly shutting of the forward sensor. Call Fellowes and see if they can help.
If you do not have the manual use the link below:
Fellowes Shredder Manuals

I have one like the one pictured. UNPLUG THE UNIT, USE GLOVES THE WHEELS ARE SHARP. Take another look at the underside see if the old paper is compacted if so, use an ice pick to pry the paper loose but be careful. Another item you will see 7 holes those are screws. Use a phillips and remove the screws to expose the working parts. Look for paper jams etc. move the wheels by hand, add a little WE40 or lite oil. Hope this helps.

look inside entry for paper and find the sensor switch. Make sure it is free and not bound up. If so unplug and clean out. GL

had mine in pieces two hours ago... look underneath the label stickers their is another screw holding the box together... you problem sounds easily fixed mine is the Nylon cog has stripped itself a worldwide problem and one that fellows is ignoring..pity they are are not like Toyota on their recalls!

UK dissatisfied customer

Sounds like a bad or dirty switch you can try to clean it with alcohol ( the switch that gets activated by the paper)
-Carl

Lube the cutting blades with shredder oil-Carl

Clean the upper and lower sensors with a cotton swab moistened with rubbing alcohol.

I’m happy to help further over the phone at https://www.6ya.com/expert/jayw_0e86fb055a7b73de

I just had the same problem. I called the 800 # they asked for proof of purchase to replace if 1 year old. I did not have it so...... I took it apart ------ unpluged ! Only to find all gears are fine, service dept. said gears cause this problem, not so with mine. Remove top by pulling of base remove 6 screws on under side, played with the switch inside a bit and, it now works, do not know how long but for know it does. My opinion is the relay gets dirty, and you cannot clean it without talking whole thing apart.

Hello,
Sounds like the internal gears or drive shafts are either broken, or out of alignment. Not exactly something that can be easily fixed usually. Hopefully, it's still under warranty?