PCB Care

Blue Star U9 Error Code

AC Power Zero Voltage Detect Error.

ac
AC Power Zero Voltage Detect Error

Cause: Zero-crossing detection circuit fault on power input

How to fix: Check zero-crossing detection circuit on main PCB.

Blue Star boards that may fix U9

If the board is the cause, these refurbished Blue Star boards are in stock. Match the part number before you order.

Other Blue Star codes

b5b7C5E0E1E2E4E5E6E8ECEE