Xerox 4400DT Service Manual - Page 85
Laser Unit Failure., U2 Laser Fail/Power Off
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Laser Unit Failure. (U2 Laser Fail/Power Off) Laser Failure at warm-up: I Transmitting /BD signal is longer than specified value for 10 sec. + t1. I The laser power does not reach the specified value. Laser Failure after warm-up: I Laser signal intervals become longer than the Fail time interval after Laser warm-up is completed. Laser Failure Troubleshooting Procedure Step Actions and Questions Yes No 1 1. Enter Service Diagnostics and 2. Select Engine NVRAM Adjustments. 3. Scroll to Laser Power and press OK. Is the value for Laser Power set to "10"? Go to step 2. Set the value to 10. If the problem persists, replace the Engine Logic Board (RRP 9.3, page 6-89). 2 Select Motors/Fans Tests then Laser Scan Motor. Go to step 3. Go to Laser Can you hear the Laser Scan Motor spin up? Assembly on page 3-17. 3 1. Switch the printer power OFF. Go to Laser Go to step 4. 2. Remove the Left Interface Cover (RRP 1.1 on Assembly on page 6-6), the Left Cover (RRP 1.2 on page 6-7), and the Left Plate (RRP 1.11 on page 6-16). page 3-17. 3. Disconnect P/J21 from the Engine Logic Board. Switch the printer power-on. 4. On the Engine Logic Board, check the voltage between P21-6 and frame ground. Is the voltage +5.0 VDC? 4 On the Engine Logic Board, check the voltage between Go to step 6. Go to step 5. P25 pin 4 and frame ground. Is the voltage +5.0 VDC? 5 On the Engine Logic Board, check the voltage between Replace the Replace the P28 pin 7 and frame ground. Engine Logic LVPS (RRP Is the voltage +5.0 VDC? Board (RRP 9.5 on 9.3 on page 6-91). page 6-89). 6 On the Engine Logic Board, check the voltage between Replace the Go to Install P25 pin 3 and frame ground. Engine Logic or Reseat Is the voltage +5.0 VDC? Board (RRP Print 9.3 on Cartridge. on page 6-89). page 2-33. 2-48 Phaser 4400 Laser Printer Service Manual
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