Mitsubishi Electric XD221U Service Manual page 45

Power source 2
Fail to light up
Check LED
indication
OK
Check
lamp life
OK
Check POWER PCB
ASSY 380V output
OK
Check lamp
power unit
OK
Check MAIN
PCB ASSY
OK
Check color wheel
rotation while
power on
Refer to LED
NG
indicator and follow
indicative actions
NG
Replace lamp
NG
Replace POWER
PCB ASSY
NG
Replace lamp
power unit
NG
Replace MAIN
PCB ASSY
NG
Replace
color wheel unit
No Volume
Check
speaker
OK
Check MAIN
PCB ASSY
-  -
NG
Replace speaker
NG
Replace MAIN
PCB ASSY