I hope this will help someone in the future.
Recently this TV came in the shop for repair. The TV came on and worked well for an hour then the symptom showed.
Power Board Nos.: PK101V25001
75024034
FSP138-3FS01
Main Board Nos.: ST055T VTV-L55710 REV 1
461C3V51L12 REV 1B
75024033
PK101V24301
T-Con Board Nos.: J128CM4C4LV0.1
LJ94-15977D #V8959
Symptom: Set turning ON and green power light on front panel lit. Video
and audio normal.
After 1-5hrs normal viewing picture will stutter and video
and audio will fail and backlights will shut down.
Green power light remain lit.
Turn set OFF then back ON and backlights will turn ON and
video and audio normal.
Picture will stutter and video and audio will fail and backlights
will shut down again.
Diagnosis: Power Board jack P802 showed the following DC Voltages (Vdc):
Pin No. StBy ON Sht Dwn
16 BLON 0 3.25 3.25
15 DIM 0 3.25 3.25
14 ACD 0 3.39 3.39
13 PWON 0 3.29 3.29
12 5Vcc 5.0 5.0 5.0
11 5Vcc 5.0 5.0 5.0
10 NC
09 12V 0 12.0 0
08 12V 0 12.0 0
07 GND
06 GND
05 GND
04 24V 0 24.0 0
03 24V 0 24.0 0
02 GND
01 GND
On shut down the 12V and 24V went missing and all other voltages BLON, PWON, DIM derived from the Main Board and ACD derived from the Power Board were remained active.
The Power Board or Main Board was suspected as defective.
ESR testing on all Main Board electrolytics are as follows:
C497-100uF xxV 0.70ohms
C495-560uF 2.5V 0.02ohms
C202-560uF 2.5V 0.02ohms
C72-220uF 6V 1.0ohms
C62-220uF 6V 1.3ohms
C196-330uF 6.3V 0.01ohms
C313-330uF 6.3V 0.01ohms
Repair: Replaced Power Board
Conclusion: TV 'burn-in' test was performed for 10, 12 and 8hrs separately
for 3days, thus proving the Power Board defective.
Though C62 and C72 ESR were high TV continued to work
without problems.
Recently this TV came in the shop for repair. The TV came on and worked well for an hour then the symptom showed.
Power Board Nos.: PK101V25001
75024034
FSP138-3FS01
Main Board Nos.: ST055T VTV-L55710 REV 1
461C3V51L12 REV 1B
75024033
PK101V24301
T-Con Board Nos.: J128CM4C4LV0.1
LJ94-15977D #V8959
Symptom: Set turning ON and green power light on front panel lit. Video
and audio normal.
After 1-5hrs normal viewing picture will stutter and video
and audio will fail and backlights will shut down.
Green power light remain lit.
Turn set OFF then back ON and backlights will turn ON and
video and audio normal.
Picture will stutter and video and audio will fail and backlights
will shut down again.
Diagnosis: Power Board jack P802 showed the following DC Voltages (Vdc):
Pin No. StBy ON Sht Dwn
16 BLON 0 3.25 3.25
15 DIM 0 3.25 3.25
14 ACD 0 3.39 3.39
13 PWON 0 3.29 3.29
12 5Vcc 5.0 5.0 5.0
11 5Vcc 5.0 5.0 5.0
10 NC
09 12V 0 12.0 0
08 12V 0 12.0 0
07 GND
06 GND
05 GND
04 24V 0 24.0 0
03 24V 0 24.0 0
02 GND
01 GND
On shut down the 12V and 24V went missing and all other voltages BLON, PWON, DIM derived from the Main Board and ACD derived from the Power Board were remained active.
The Power Board or Main Board was suspected as defective.
ESR testing on all Main Board electrolytics are as follows:
C497-100uF xxV 0.70ohms
C495-560uF 2.5V 0.02ohms
C202-560uF 2.5V 0.02ohms
C72-220uF 6V 1.0ohms
C62-220uF 6V 1.3ohms
C196-330uF 6.3V 0.01ohms
C313-330uF 6.3V 0.01ohms
Repair: Replaced Power Board
Conclusion: TV 'burn-in' test was performed for 10, 12 and 8hrs separately
for 3days, thus proving the Power Board defective.
Though C62 and C72 ESR were high TV continued to work
without problems.
