M452 M454 M455 E45028 M377 M477 M479 M480 E47528 HP Engine Communication Error CF388-60116

M452 M454 M455 E45028 M377 M477 M479 M480 E47528 HP Engine Communication Error CF388-60116

Service Advisory: Engine Communication Errors After Component Replacement

Affected Models: HP LaserJet M452, M454, M455, E45028; MFP M377, M477, M479, M480, E47528.

Issue Description Technicians may encounter an "Engine Communication Error" following internal repairs that require disconnecting the Flat Flexible Cable (FFC/ribbon cable) between the engine controller and the formatter board.

Associated symptoms include:

• Display panel failure (blank or unresponsive).

• Printing solid-color pages.

• Missing colors in print output.

M45, M454 M455 E45028 M377 M477 M479 M480 E47528 HP Engine Communication Error CF388-60116 Formatter to Engine Controller Flat Flex Cable

Root Cause Analysis The error is almost exclusively caused by physical damage to the ribbon cable connectors during removal or reinstallation.

• Pin Damage: The pins on the cable ends are delicate and easily bent, broken, or misaligned if forced.

• Connector Sensitivity: The formatter-side connector is particularly prone to damage. Even slight misalignment prevents communication between the engine and the formatter, triggering the error.

Prevention & Best Practices To prevent damage during future repairs:

1. Prefer the Engine Side: Whenever possible, disconnect the cable only from the engine controller side. Avoid disconnecting the formatter end unless absolutely necessary.

2. Unlock First: Ensure the locking clip (ZIF connector) is fully released before removing the cable.

3. Handle with Care: Pull the cable straight out without twisting, angling, or applying uneven pressure.

4. Inspect: Visually inspect pins for bends or peeling before re-seating the cable.

Resolution If the cable or pins are damaged, the cable must be replaced. Replacement Part Number: CF388-60116