HP Color LaserJet 8500 Service Manual - Page 488

FLEntry 1 sensor and FLEntry sensor If the sheet does not arrive to the FLEntry 1 sensor within three seconds, the device declares a jam 02. When the sheet arrives at the FLEntry 1 sensor, which means that the sheet is being pushed by the printer and pulled by the device, the timer is reset to timeout in one second. If the sheet does not arrive at FLEntry sensor in one second, the device declares a jam 03. Next, the FLEntry 1 sensor is deactivated. Because this event depends on the media length and the printer speed, it is independent of time. The device counts steps in the receiving stepper motor. With the proper relation of steps to length, the device knows when the sheet leaves the printer rollers. At that time, the device switches to high speed and begins a timeout of one second. If the sheet fails to leave the FLEntry 1 sensor in one second, the device declares a jam 04. Once FLEntry 1 is deactivated, a timeout of .75 seconds begins to the next event-deactivation of the FLEntry sensor. If the FLEntry sensor is not deactivated, the device declares a jam 05. If the FLEntry sensor is deactivated, a timeout of 1.5 seconds begins for activation of the FLExit sensor. FLExit sensor If the FLExit sensor is not activated within the timeout, the device declares a jam 0A. FLExit sensor deactivation depends on the internal paper path speed and the media length. The device declares a jam when internal step counter exceeds 133% of number of steps that represent the media length. If the FLExit sensor is not deactivated, which can occur when sheet stops in the paper path because of an obstruction or slipping, the device declares a jam 0B. When the FLExit sensor is deactivated correctly, a timeout of 1.5 seconds begins for activation of the registration wheel's sensor. GWSens sensor/Exit sensor If the GWSens sensor (in the stapler/stacker) or the Exit sensor (on the stacker) is not activated within the timeout, the device declares a jam 12. 486 Chapter 7 - Troubleshooting EN