Removal and replacement strategy
WARNING! Turn the product off, wait 5 seconds, and then remove the power cord before
attempting to service the product. If this warning is not followed, severe injury can result, in addition to
damage to the product. The power must be on for certain functional checks during problem solving.
However, the power supply should be disconnected during parts removal.
Never operate or service the product with the protective cover removed from the laser/scanner
assembly. The reflected beam, although invisible, can damage your eyes.
The sheet-metal parts can have sharp edges. Be careful when handling sheet-metal parts.
CAUTION: Do not bend or fold the flat flexible cables (FFCs) during removal or installation. Also, do
not straighten pre-folds in the FFCs. You must Make sure that all FFCs are fully seated in their
connectors. Failure to fully seat an FFC into a connector can cause a short circuit in a PCA.
NOTE: To install a self-tapping screw, first turn it counterclockwise to align it with the existing thread
pattern, and then carefully turn it clockwise to tighten. Do not overtighten. If a self-tapping screw-hole
becomes stripped, repair the screw-hole or replace the affected assembly.
Electrostatic discharge
CAUTION: Some parts are sensitive to electrostatic discharge (ESD). Look for the ESD reminder
when removing product parts. Always perform service work at an ESD-protected workstation or mat. If
an ESD workstation or mat is not available, ground yourself by touching the sheet-metal chassis before
touching an ESD-sensitive part.
Protect the ESD-sensitive parts by placing them in ESD pouches when they are out of the product.
2 Chapter 1 Removal and replacement ENWW
For more information and parts on the HP LaserJet Pro 400, M425 call 800-551-1943 or order on line at www.printersupplies.com