HP 8550mfp Service Manual - Page 424

Notes Developer motor test Visually and audibly inspect the cartridge motor (M3) and carousel motor (M1) as they rotate during this test. To view the printer components, run the test with the right upper door open and the transfer drum removed and the front cover and right upper door interlocks defeated (see figure 218 on page 427 and figure 214 on page 425). The engine runs this test for a fixed duration and then stops. Multiple repetitions of the test are allowed. For safety reasons, the fuser, high-voltage supplies, and scanner are all turned off during testing. The carousel cannot turn with the imaging drum removed because the supply voltage to the carousel is cut off to avoid a pinch hazard. 1 From the Service Mode Menu, press MENU until DEVELOPER MOTOR appears. 2 Press ITEM until REPETITIONS appears. 3 Press - VALUE + to display the possible number of repetitions. 4 Press SELECT to choose the number of repetitions. 5 Press ITEM until EXECUTE TEST appears on the display. 6 Press SELECT to perform the developer motor test. 422 Chapter 7 - Troubleshooting EN