Sony KDL-32R420A Service Manual page 23

2) 3 times blinking (Main Board Error)
3-time blinking
Check PWM_5V at
L202 pin-2 on Main board
(4.75~5.25V)
OK
Check SYS_3.3V
at U204_Pin-6
on Main Board
(3.135~3.465V)
OK
Check the harness
M/B to Speaker
connection
NG
Fix the harness
connection
KDL-32R420A/421A/423A/424A, 40R470A/471A/473A/474A, 46R470A/473A(AEP/UK)
DC_ALERT
NG
U202, L202, etc
Change Main board
NG
U204, etc
Change Main board
Check the speaker
OK
Impedance at the
SP Connector
(8ohm+/-15%)
OK
AUDIO
NG
Change Speaker
Demo, Audio, Tuner, etc
Change Main board
TROUBLE SHOOTING
23