Service approach
Product repair normally begins by using the product internal diagnostics and the following two-step
process:
1.
Isolate the problem to the major system (for example, the network, the server, or the product).
2.
Troubleshoot the problem by using the procedures in the solve problems chapter of the
Troubleshooting Manual.
After you find a faulty part, the product can usually be repaired at the assembly level by replacing field-
replaceable units (FRUs). Some mechanical assemblies might need to be repaired at the subassembly
level.
Before performing service
●
Remove all paper from the product.
●
Turn off the power using the power switch.
●
Disconnect the power cable and interface cable or cables.
●
Place the product on an ESD workstation or mat, or use an ESD strap (if one is available). If an
ESD workstation, mat, or strap is not available, ground yourself by touching the sheet-metal
chassis
before
touching an ESD-sensitive part.
●
Remove the toner cartridges. See
Toner cartridge on page 11
.
●
Remove the tray or trays. See
Tray 2 or Tray 3 assembly on page 13
.
After performing service
●
Connect the power cable.
●
Reinstall the toner cartridges.
●
Reinstall the tray or trays.
●
If an optional paper feeder was installed, place the product on the feeder.
Post-service test
Perform the following test to verify that the repair or replacement was successful.
Print-quality test
1.
Verify that you have completed the necessary reassembly steps.
2.
Make sure that the tray contains clean, unmarked paper.
3.
Attach the power cable and interface cable or interface cables, and then turn on the product.
4.
Verify that the expected start-up sounds occur. The fans start.
ENWW
Service approach
5
Summary of Contents for LaserJet Pro M521
Page 1: ...LASERJET PRO MFP Repair Manual M521 2 ...
Page 2: ......
Page 3: ...HP LaserJet Pro MFP M521 Printer Repair Manual ...
Page 6: ...iv Conventions used in this guide ENWW ...
Page 10: ...viii ENWW ...
Page 14: ...14 mm 4 Chapter 1 Removal and replacement ENWW ...
Page 148: ...138 Chapter 1 Removal and replacement ENWW ...
Page 155: ...ENWW Assembly locations 145 ...
Page 186: ...176 Chapter 2 Parts and diagrams ENWW ...
Page 189: ......
Page 190: ... 2012 Hewlett Packard Development Company L P www hp com A8P79 90904 A8P79 90904 A8P79 90904 ...