I have a 4550 thats giving the old 50.7 fuser error. I replaced the following
two different fusers
LVPS - two different
HVPS - don't know why, but I figured both PS's
fuser motor M2 - two different
Feed (fuser) PCB
Fuser sensor PS6
DC Controller

I checked the gears adjacent to the fuser motor - they spin OK
I checked relevant cables with a OHM meter
The fuser motor doesn't turn during bootup (like it should)

Before taking this all apart to replace the fuser power connector and other misc parts, has anyone run into a case where this 50.7 fuser error was caused by some strange part causing a chain reation.

Thank you, Doug O