mp-4500

[T911]

can't get rid of sc322. replaced the laser motor and diode, reset and calibrated the laser, checked my door switches ok. what the f--- with this one. machine runs dirty as hell though. thanks t

[Shadow1]

That leaves the Polygon motor (should give a 320 if bad), the sync detect board, dirty or misaligned optics, harness and BCU.

Check the optics - that's free - then the sync board seems most likely to me.

[tcs04]

can't get rid of sc322. replaced the laser motor and diode, reset and calibrated the laser, checked my door switches ok. what the f--- with this one. machine runs dirty as hell though. thanks t

If it runs dirty I would change the switches above the fuser. They may meter out ok but fail when under load.

[mikadonovan]

If it runs dirty I would change the switches above the fuser. They may meter out ok but fail when under load.

I would say door switches, too. Once they get tonered up they become intermittant and cause the exact kind of problem your experiencing.