Fellowes 225ci shredder. Do I need to replace photo sensors?

Check and make sure there is no paper or paper dust covering the Bin Full sensor. underneath the head.

Use a cotton bud dipped in alcohol and clean sensors
Run shredder once a day in reverse for 15 seconds to clear cutters
Empty wastebasket when bin full indicator light is illuminated using b0
If this does not solve the problem goto
www.fellowes.com for an extensive on-line support section

Unplug from mains electricity.
use a cotton bud dipped in rubbing alcohol to clean the sensor
light(s) and heads
Give a quick spray to cutters with WD40 Replace - turn on - and run in reverse.
If all else fails, contact the maker

If you look into the slot you feed the paper into, you should see a two little bumps that are facing each other in the center of the slot. These are the sensors that tell the unit to turn on/off. You can try cleaning them with a paper towel or long q-tip. If this does not fix it, then the sensors will have to be replaced. Most Fellowes machines have a 3-year warranty, you can call Fellowes at 1-800-955-0959 to see if yours is under warranty.

Your Fellowes p600c-2 shredderappears to have the same problem I had, it would run in reverse but would not shred new paper. I removed the 6 screws that are visible on the top assembly, but could not get the top assembly to come apart. There is a seventh screw hidden under one of the adhesive labels. I removed that screw and was able to disassemble the shredder. The plastic trigger mechanism that starts the shredder when paper is put in was stuck. I freed the trigger mechanism and reassembled the shredder. Now it works fine.

Have you tried calling Fellows? This link is to your operating instructions, which has phone numbers listed for different countries.
http://www.fellowes.com/Fellowes/Materials/Documents/ds1_2005manual.pdf
This link is for listing your model and serial number to inquired about what parts are available.
http://www.fellowes.com/Fellowes/site/support/support_faq.aspx

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

You need to clean the paper feed sensors. You can call Fellowes customer service at 1-800-945-4545

Though I only work with Fellowes shredders this sounds like a paper feed sensor issue. If your unit has a mechanical paper feed sensor you can try to jiggle it in and out to see if any paper may have become jammed behind switch. If the unit has an electronic sensor it may simply need to be cleaned with a Qtip dipped in rubbing alchohol.
If neither of these help your paper feed sensor or your pc board has gone bad and you will have to contact your manufacturer for further parts availability.

Seems it could be a problem with one of your sensors Fellowes Customer Service can easily and quickly diagnose your problem. 1-800-945-4545