HP 55.x — DC controller communication error

What this error means

The engine control board and formatter stopped talking to each other — board, cable, or power-supply issue.

Symptoms

• Error at boot
• Random restarts

Try this first (safe DIY steps)

1. Power off, unplug for 60 seconds, power on
2. If recently moved or serviced, a tech should check board seating

Safety: power off before any physical intervention. Never bypass covers or interlocks — fuser areas run hot enough to burn.

When to call a technician

If persistent — board-level repair.