Troubleshooting; No Power - Sony KDL-32R420A Service Manual

SEC 3. TROUBLE SHOOTING

3-1. NO POWER

No power
Long AC off(> 15 min.)
and then
Power On
NG
Check SB_3.3V
at 1 pin of CN201
on the Main board
Between 3.14~3.45V
OK
Change
Main board
KDL-32R420A/421A/423A/424A, 40R470A/471A/473A/474A, 46R470A/473A(AEP/UK)
OK
Enter Service Mode and check
Self diagnosis history
Check the harness
NG
PSU to M/B
connection
NG
Fix the harness
connection
IF MAIN_POWER > 0 or
DC_ALERT1 > 0
IF AUDIO_PROT > 0
BACKLIGHT_ERR > 0
Replace the harness
OK
between PSU and
Main board
OK Symptom
improvement
Harness issue
Yes
Change
Main board
No
Yes
Change
Main board
No
Yes
Change
Panel
NG
Change
PSU
21