Acer A221HQV Acer A221HQV LCD Monitor Service Guide - Page 39

5. Troubleshooting (continued) 5.2.3 Checking the back light unit: ACER A211H/A221HQ 37 Go to contents page Is +22V supplied to inverter PWB? (by the power board) Failure Point NG 1) The wire between Power +22V and Inverter +22V is broken. 2) Power board failure. OK Check the BACKLIGHT_ADJ signal of the CN301 pin 13 from I310 pin 114 is a PWM signal. Failure Point 1) Printed wire broke between CN301 NG pin 13, and I310 pin 114. 2) R301 is open. 3) I310 is failure. OK Failure Point Back light unit of LCD module is failure.