Canon E804 — Power supply fan error

What this error means

A power-supply cooling fan stopped (lock signal detected while driven). Dust is the usual assassin. The detail code identifies which fan.

Symptoms

• Error after long runs
• Fan noise changed or stopped

Try this first (safe DIY steps)

1. Power off; vacuum accessible vents (don't open service panels)
2. Ensure wall clearance per the manual
3. Power cycle

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

When to call a technician

Fan replacement — quick for a tech, behind panels.