Sharp Aquos LC-52D64U - Flashing Power

[jbandy]

I was able to get a Sharp Aquos LC-52D64U for free in a non working condition.

When I originally powered it up, I was getting two blinks of the power light and one blink of the OPC Light (Power and OPC would blink once together, then Power would blink once by itself, then repeat). Voltage showed that with Inverter1 connected, it would never get 60V. If I unplugged connector LA1 (Which goes to Inverter 1), I would show 60V on the power supply, so I replaced two of the four inverters (Inverters 1 (RUNTKA327WJZZ) and (Inverter 3 RUNKA329WJZZ) and was able to power up and get picture/sound, etc. I noticed there's two small vertical lines (green and red) running the full length of the screen on the right hand side (Where Inverter 1 and Inverter 2 is installed) I'm thinking maybe that's a seperate issue (Bad tab bond?)

On a cold start, I can turn it on and watch hours of movies, etc with it. If I turn it off and immediately turn it back on, every other row of tubes on the backlight looks like it's flickering, then the backlight goes completely out (can still hear sound) but then you hear a click and the tv turns off and the power light blinks on and off (single blink continuously)

If I turn it off and let it sit for a few minutes, I can turn it back on and watch normally again for hours more.
I have reset the Lamp Error count and the Monitor Error Cause Count and done a factory init from the service menu.
Monitor Err Cause is continuing to increment when this happens but lamp error doesnt increment.
Whats my next step in troubleshooting? Where should I be looking at? Inverters? Power Supply? Tubes?

One other thing I've noticed, is sometimes, I can hear a high pitched hum come from either Inverter1 or Inverter2 (Might be both of them) Inverter1 is one of the boards i replaced.

Below are the power voltages coming off the Power Supply Board

LA2 Connector (Goes to Inverter 1)
60V 61.4V (When Screen Flickers 61.3V)
12V 11.9V - 12V (When Screen Flickers 11.9V)

LA1 Connector (Goes to Inverter 3)
60V 61.2V (When Screen Flickers 60.9V)
12V 11.8-11.9V (When Screen Flickers 11.8V)

Here are the voltages for the PD Connector when TV is Working.
LNB 0V (No Cable)
LNB-POW 0V (No Cable)
LNB-CONT 0V (No Cable)
PS-ON 2.6V
AC-DET 2.9V-3.0V
PNL-POW 3.2V
SGND 0V
BU5V 4.9V
SGND 0V
SGND 0V
UR15V 14.6V
UR15V 14.6V

[jbandy]

Re: Sharp Aquos LC-52D64U - Flashing Power

BUMP! Anybody?

[jbandy]

Re: Sharp Aquos LC-52D64U - Flashing Power

Bump

[jbandy]

Re: Sharp Aquos LC-52D64U - Flashing Power

Bump

[jbandy]

Re: Sharp Aquos LC-52D64U - Flashing Power

Anybody?

[jbandy]

Re: Sharp Aquos LC-52D64U - Flashing Power

Cmon guys. Just need a little help. Not sure if I should take this whole thing apart and examine the CCFL's or what (That's a big job)

[budm]

Re: Sharp Aquos LC-52D64U - Flashing Power

Do you have capacitor tester to check the capacitance AND the ESR of those caps on the inverter boards? I would try new caps first before taking the panel apart, the caps will have to be replaced sooner or later anyway.

[kc8adu]

Re: Sharp Aquos LC-52D64U - Flashing Power

any sign of pink lamps on cold start?
i have one now 46" with a pink lamp and has problems once lamps warm up.
if one is sick may as well replace all but with your lines i would run it till it dies for good.

[jbandy]

Re: Sharp Aquos LC-52D64U - Flashing Power

Do you have capacitor tester to check the capacitance AND the ESR of those caps on the inverter boards? I would try new caps first before taking the panel apart, the caps will have to be replaced sooner or later anyway.

All I have is a digital voltmeter. Bought inverters 1 and 3 off of ebay and that's what allowed me to actually power up the tv. Don't see any bulging caps, etc.

[jbandy]

Re: Sharp Aquos LC-52D64U - Flashing Power

any sign of pink lamps on cold start?
i have one now 46" with a pink lamp and has problems once lamps warm up.
if one is sick may as well replace all but with your lines i would run it till it dies for good.

No, looks pretty white to me. I paused a blueray on a white screen (one of the attachments, not a perfect white screen, has a fade out to a skull or something). As far as the lines running up and down the screen, looks like tab bond issue to me. Was going to investigate that further if I had to take the screen completely apart (which I dread doing). Figured I would work on the tab bond at the same time I inspect the CCFL's, but wanted to get some opinions of you guys before I dive that deep. I can live with the lines, but it's bugging me that the tv is going into protection mode if I turn it off / back on after it's warmed up.

[R_J]

Re: Sharp Aquos LC-52D64U - Flashing Power

I have had a problem with the a couple master (upper) inverter boards causing a flicker and shut down problem, I had another board to replace it with so I never did diagnose the problem to component level. I did check my other lower (slave) inverters and they were ok.