HP Designjet 250c Service Manual - Page 187

230 250C Servo/Encoder Test The servo/encoder test performs the following: D MediaĆaxis encoder test: Verifies the operation of the servo loop (mediaĆaxis feedback). D CarriageĆaxis encoder test: Verifies the operation of the servo loop (carriageĆaxis feedback). D Records the maximum pulseĆwidth modulations used. You can view this information on the service configuration plot. 1 In service mode 2: 230 250C Hold down the ALT key and press Servo/Encoder Test. 330 350C Press Servo/Encoder Test. ALT Servo/Encoder Test Servo/Encoder Test The Load Media LED (or the Ready LED, if you have already loaded media) turns off, and the carriage moves over the left end of the roller. The roller rotates slightly. The carriage moves to the center of the plotter. Both the carriage and the roller then move backwards and forwards in cycles of six short steps, changing direction between cycles. 2 Press any frontĆpanel key to stop the test. Status. If the test does not find an error, the Load Media LED (or the Ready LED, if you have already loaded media) turns on again. If the test finds an error, it is indicated by an error code on the front panel. Stored in EEROM (and printed on the service configuration plot ' page NO TAG) Encoder Tests, Maximum Y-Axis PWM (Y-Axis = Carriage Axis.) This should be less than 102. Typical value = 75. Encoder Tests, Maximum X-Axis PWM (X-Axis = Media Axis.) This should be less than 65. Typical value = 52. C4699Ć90000 Troubleshooting 8Ć53