!
error HP
Error Code 40 Bad Serial Trans
Bad serial transmission error indicating communication problem.
? What Causes This
Serial communication error between computer and printer, faulty cable, or connection issue.
✓ How to Fix It
- Press the Go button to continue.
- Check and reseat the serial cable.
- Verify cable is not damaged.
- Try a different serial port.
Source: page 142 of the official manual
From the manual
This error code appears in:
HP Laserjet 1010 Printer