Sharp lc-52d64u flashing green power LED, won't turn on

[Ifixstuff9]

My sharp lc-52d64u has a flashing green power light whenever I try to power it on. The light flashes once every 1.5 seconds.

If I hold down [vol-] and [input] when I apply power to the TV I can hear a relay click and the backlight will flash on and off multiple times, as you can see in this video: https://youtu.be/I-J6n2XXWmw. It appears that every other tube isn't lit, as indicated by the dark rows running across the screen. After a few seconds the screen turns off, the relay clicks, and the power LED starts flashing again.

If I disconnect the inverter board on the left of the TV and leaving the right connected, you can see in this video: https://youtu.be/uRFizk37lwo that the backlight lights up nice and bright and doesn't flash when I power it on holding [vol-] and [input]. It eventually turns off and the TV resumes the LED code.

I didn't see any bad caps inside the TV. At this point I'm pretty sure I have bad inverter board(s) on the left side of the TV, but before I buy new ones I would like to do some more troubleshooting to be completely sure of the problem.

I have attached pics of the boards and the service manual can easily be found online.

[CapLeaker]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Witch the inverter boards disconnected, take your DMM, put it in Ohm's mode and compare the output winding of each transformer. If there is a difference from more than 3%, then the transformer is bad.

Looks like the inverter on the right side isn't firing up.

[Ifixstuff9]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Thanks, I'll try that as soon as I find my multimeter.

[Ifixstuff9]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Hmm, I tested all of the small transformers and they seem fine. I can't find out how to test the bigger ones, which pins should I test? Here is a pic of the transformer's pins.

[dskall]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Have those traces gotten hot?

[Ifixstuff9]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

I'm sure they have gotten hot during use, but I haven't tried heating them up myself. Now that you mention it, a lot of the traces on the board appear to be in bad shape.

[Ifixstuff9]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Any idea what the component in the center of the attached picture is? I think its either a capacitor or a diode, but I could be wrong. It doesn't have any discernible writing on it.

[cliff_hootarski]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

D7503c - Diode

[Ifixstuff9]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Ok thanks. Is there any way I can test that diode in circuit? I have a feeling it might be bad.

[jdlowvoltage]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Any update on this?? I have the same model (lc-52d64u). Flashing green power LED. i replaced the power board with the same result. I can use Vol- and Input to turn it on in service mode and I actually get a picture for about 5-10 seconds. Then i hear a relay and it kicks back off. I unplugged both inverters and tried the same sequence with the same result.

[jdlowvoltage]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

BUMP... Anyone?

[CapLeaker]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Is it like 3 seconds to black?
check the output winding of the transformers on the inverter board's. Compare them to each other. If one is out by 3%, that's the bad one. Other than that, bad caps, bad solder joints or a bad ccfl.

[augiedoggy]

Re: Sharp lc-52d64u flashing green power LED, won't turn on

Is the OPC light flashing too? the lights should give you an error code... I have the same model set and the #3 inverter board (there are 4 boards) is bad... I get the opc light flashing once and the power light flashes twice, Once with the opc light and once without.. the book said its a power supply fault but it wasnt.. unplug #3 inverter and the set powers up for a few second (without holding any buttons)... plug it back in and the set just clicks on and off..