Sharp TV - Solid Red Light

[Rainy]

So, I've been through almost three power supplies on this TV now

The first was all sorts of bad....

The second I got a solid red light, thought it was the standby.... That came from ebay without being in a anti-static bag.

I got another one, and it does the same exact thing from the same seller.


https://www.sharptvusa.com/support/l...u/users-manual

The TV in question above.


Any help is appreciated, do you guys think a firmware flash would help? I really can't afford to order more parts for the TV if they won't work.

[Andrew F. Ali]

Re: Sharp TV - Solid Red Light

We need pictures of the TV with the back cover removed to see the boards. Have you taken any voltage measurements? If so what are they? You question is valid but vague. I would think we need more information from you as we do not have the TV or the PSU in front of us and to do along distant troubleshoot, photos are a must.

[Rainy]

Re: Sharp TV - Solid Red Light

We need pictures of the TV with the back cover removed to see the boards. Have you taken any voltage measurements? If so what are they? You question is valid but vague. I would think we need more information from you as we do not have the TV or the PSU in front of us and to do along distant troubleshoot, photos are a must.

ok, just tired..

The 18V reads 21.5v

the 12v reads 12v

the STB reads 85mv

the SW and other hot leads are about 0.1mv

The grounds are all 0

But this set is so new I don't think the board has a diagram. I tried fixing the last two boards thinking something is wrong with the STB, but I get a red light on. I also spliced the STB to maybe feed 5v dc into it.

[Andrew F. Ali]

Re: Sharp TV - Solid Red Light

I can't see the photos. The voltages are not correct. can you confirm that your DMM is working properly and what did you use a GND?

[budm]

Re: Sharp TV - Solid Red Light

STB = PS-ON
SW = BL-ON
PWM = PWM Dimming
So your main board is not sending those command signals, they should toggle when switching the TV power ON and OFF.

[Rainy]

Re: Sharp TV - Solid Red Light

I can't see the photos. The voltages are not correct. can you confirm that your DMM is working properly and what did you use a GND?

What is the DMM? I just used the tv ground as ground, like a screw hole. Works great.

STB = PS-ON
SW = BL-ON
PWM = PWM Dimming
So your main board is not sending those command signals, they should toggle when switching the TV power ON and OFF.

This is why I was wondering if there is a firmware somewhere I can re-flash the tv with.

[Andrew F. Ali]

Re: Sharp TV - Solid Red Light

DMM is Digital Multi-Meter.. ...I don't think it is a Firmware issue, but do think that the Main Bd has a problem.

[Rainy]

Re: Sharp TV - Solid Red Light

DMM is Digital Multi-Meter.. ...I don't think it is a Firmware issue, but do think that the Main Bd has a problem.

I would kind of agree with you at this point but I want to test my backlight.

How can I jump start the power board to test the backlight?

Thanks.

This is the top-down view of the board (my camera is dead):

[Andrew F. Ali]

Re: Sharp TV - Solid Red Light

Disconnect the connector on the PSU that goes to the Main Bd. Connect two (2) AA batteries in series to give 3V. On the underside of the PSU on the connector that would have gone to the Main Bd. very carefully solder the battery +ve to the STB=PS-ON pin and on the SW=BL-ON pin (as described in Post #5)and the battery -ve to the GND pin. Inspect your soldering to verify there are no shorts to adjacent pins and the connections you made are solid. Plug in the ac and if the PSU is good the Backlights should come ON. Measure for other voltages generated on the PSU are correct and if the are then your PSU and Backlights are good.