Sharp LC-50UB30U no backlight

[landyboy]

Have the above TV isolated it to the Led? There is a picture on the panel with sound but no backlights. Looking at the board it appears to have 2 strings of Led's. Testing from ground to Voltout1 and Voltout2 both voltages are 89.1VDC with led strings plugged in or unplugged. Seems low but I haven't worked on many led units yet. What voltage should I be seeing on those pins? Am I reading it correctly?

Thanks

[landyboy]

Re: Sharp LC-50UB30U no backlight

After more testing it appears when I first turn the power on with ledss trips unplugged it starts at about 115 vdc then settles to 85vdc. If I do it with leds plugged in its starts at 30vdc and continues to go down. I'm assuming some sort of protect mode.

[budm]

Re: Sharp LC-50UB30U no backlight

But how about the Voltage reading on LED1 and LED 2 pins with ref to the chassis GND?
You need to keep the meter probes in place while turning on the TV so you can see what the Voltage shows each time you turn on the TV, you will be doing that twice.

[landyboy]

Re: Sharp LC-50UB30U no backlight

I decided to take the set apart down to the led strips. Put some 9v batts in series and tested each strip. On the bottom strip all but 4 lit up brightly, 2nd and 3rd strip from the bottom nothing at all and the top strip had about half of the lights come on dim. Pretty sure I have a bunch of bad Led's. No replacement strips available anywhere....

[budm]

Re: Sharp LC-50UB30U no backlight

What is the LCD panel model number, when you get that then you can search for the LED strips that will fit that panel.

[landyboy]

Re: Sharp LC-50UB30U no backlight

T500QVN02.0 really can't find anything out there this panel. I did get a quote for a repair on the strips though.

[budm]

Re: Sharp LC-50UB30U no backlight

I just search the web using that model:
http://www.shopjimmy.com/hisense-rsa...rips-50h7c.htm

[mmartell]

Re: Sharp LC-50UB30U no backlight

Lol

[Andrew F. Ali]

Re: Sharp LC-50UB30U no backlight

I just search the web using that model:
http://www.shopjimmy.com/hisense-rsa...rips-50h7c.htm

Looks like this will work for your TV. If you can get the spacing measurement between LEDs to see if they match yours, go ahead and replace ALL the strips and get your baby up and running again.