Sharp LC-50LB370U Where to buy LED Strips?

[Gorrillasnot]

I was given this TV for free. The lady that owned it said it was approximately 14months old.
When turned on it blinks 7 times and then the screen comes on, but without back lights. I can shine a flash light on the screen and see an image.
From researching it appears these TVs are prone to LED failures, which brings me to my question.
A popular online TV parts site wants $64.95 for a set of strips..is this the best option ( I don't have the tools or experience to replace individual LEDs)
Is there any cheaper generic alternatives that would work?

I wouldn't mind spending the $64.95, but with the high risk of breaking the screen on reassembly from a novice like myself to the fact that the originals lasted just over a year I hate to risk much money.

thanks

[diif]

Re: Sharp LC-50LB370U Where to buy LED Strips?

If you can't/don't want to replace the individual LEDs, new or second hand strips are the only way to go.

Are these them ? https://www.ebay.com/itm/SHARP-LC-50...P/272971606694

[zdsh07p9]

Re: Sharp LC-50LB370U Where to buy LED Strips?

Gorilla,

A novice can do this with a lot of PATIENCE. Don't man handle anything if its difficult to get out (the screen especially). You had to take the back off, disconnect the TCON ribbon cables (from the boards connected to the screen to the TCON), flip over the TV and unscrew the front bezel piece from around the sides, take off the front bezel piece which reveals the LCD screen. There shouldnt be anything else holding down the screen, but be careful not to flex or bend the LCD screen at any time during removal. After removing the screen youll see layers of thin clearish/white plastic - takes those off but note the order they are in because youll have to put them in exactly like that when rebuilding. Under those youll find the LED strips. To remove the LED strips youll have to remove the white backing that is over them, and in order to do this there are usually little locks that keep it in place that need to be loosened from the back of the TV (from most of my experiences). Remove them and then take out the white backing, now you can really see the LED strips. Youll have to unscrew or untape the LED strips to remove (and unplug/disconnect them). Replace the strips and then TEST it really quick! You'll have to hook power up to an open TV (front and back open) so be CAREFUL. If the power button isn't connected youll have to reconnect it at this stage so that you can power it on to test. You shouldn't have to connect the TCON ribbon cables back up to the TV to test. Once you see the LEDs light up you know you're good. Now put everything back and be CAREFUL!

Z

[dskall]

Re: Sharp LC-50LB370U Where to buy LED Strips?

Most important part is to make sure to get panel seated in plastic bezel before putting on metal strips. Panel should rest slightly below plastic edge. Especially check corners.

[petehall347]

Re: Sharp LC-50LB370U Where to buy LED Strips?

also beware of dust .

[Gorrillasnot]

Re: Sharp LC-50LB370U Where to buy LED Strips?

thanks everyone for all the info/tips.

The factory that made this TV must have been overstocked on glue because almost everything had glue on it. The bezel was screwed and glued, the LCD screen itself was glued to the chassis in 4 places. I used a guitar pick and got it free without damage so far..knock on wood.
I am now stuck on the white paper backing that covers the strips. I removed the clips, but it is also glued to the metal frame in various spots around the outer edges. I stopped for the night in fear of ripping it. Any ideas on how I can remove it without damaging it? If I do tear it is it game over or can it be taped or otherwise repaired?

shopjimmy lists 3 compatible part numbers for the LED strips 500TT65/500TT66, 500TT61/500TT62, or 500TT25/500TT26 and they are ruffly $75 shipped for a set of 12. (I've googled/ebay'd the cheapest from all three part numbers)
In the grand scheme of things that isn't that much to invest in a 50" TV, but at the same time it seems to be a costly gamble especially since i am a newb and there is significant risk of disaster on reassembly.
Are there any cheaper options or should I just man up and pay the $75?

thanks

[diif]

Re: Sharp LC-50LB370U Where to buy LED Strips?

The much cheaper option is to replace just the faulty LEDs.

[Gorrillasnot]

Re: Sharp LC-50LB370U Where to buy LED Strips?

Using a single edge razor blade as a scraper I have still managed to damage the white paper backing. Is it game over or can this be repaired?
If repair is not an option does anyone sell replacements?

Not only is the paper backing glued in various spots along the outer edge it is also glued at numerous spots on the bottom.
It's not the easy gummy glues that I have normally found used in electronics, but tough hard dried glue..A real pain it the butt.

Regarding the LEDs by the time I bought the tools required to test and replace the individual LEDs I would probably have close to the same amount invested as I would if I were to buy the new strips (tools would be nice for future TV repair though). Plus if a few LEDs are failed now, more could follow shortly.

I haven't ordered anything yet, but I think I will just get it over with and pay up for the new strips, provided the damaged paper backing isn't game over?

thanks

[dskall]

Re: Sharp LC-50LB370U Where to buy LED Strips?

Tears in backing will not hurt anything

[Gorrillasnot]

Re: Sharp LC-50LB370U Where to buy LED Strips?

Thanks for the info dskall, that is a big relief.

I made a little further progress, I'm not sure if I'm doing this right or not, but the strips have + and - spots next to each LED and with my DMM set to diode mode I tested each LED and all but 3 would light up.

I have a cheap harbor freight heat gun and have seen a youtube video of a guy using a similar one to desolder a LED, but he knows what he's doing.

Would I be wise to just go ahead and replace all the strips with new ones or should I take a gamble and try to replace only the 3 bad ones?
It would be nice if I could find individual strips for a reasonable price, but I haven't had any luck finding any on ebay.

If you think I should try replacing the 3 bad LEDs which ones would I need?

thanks

[Gorrillasnot]

Re: Sharp LC-50LB370U Where to buy LED Strips?

I'm thinking about buying some LED strips thats been cut in pieces like these https://www.ebay.com/itm/50Pcs-3V-SM....c100276.m3476 and use the stacking metod to replace the 3 bad LEDs..How do I tell if I need 3v or 6v LEDs?

thanks

[dskall]

Re: Sharp LC-50LB370U Where to buy LED Strips?

All strips I have seen except edge lit are 3v

[Gorrillasnot]

Re: Sharp LC-50LB370U Where to buy LED Strips?

I ended up ordering these https://www.ebay.com/itm/50pcs-3V-SM...53.m2749.l2649.

There was a total of 4 bad LEDs, I replaced them using the stacking method, plugged in the TV and turned it on and nothing..not even a flash.
I then tested each individual LED w/ my DMM in diode mode and they all will light up.

Next I flipped the TV over to test voltages.
Power connector going from top to bottom.
15.v = 0v (standby and power on)
12v = 11.8v
12v = 11.8v
12V_A 11.8v
GND
GND
PS_On = .12v standby and 3.7v power on
1. DIM = 0 standby and 3.2v power on

LED Connector.
+VLED2 = 65.4v standby. power on and it spikes to 96.4v then settles back down to 65.4v
+VLED1 = Same as above.

When plugged in and powered off I get a red standby light. When I press the power button the light blinks red 7 times and then turns blue.

The first pic is of the power board borrowed from shopjimmy. The rest are from my TV.

Where do I go from here?

thanks

[dick_barton]

Re: Sharp LC-50LB370U Where to buy LED Strips?

That still looks as though you have a led(s) / led chain connection problem.

[Gorrillasnot]

Re: Sharp LC-50LB370U Where to buy LED Strips?

That still looks as though you have a led(s) / led chain connection problem.

That's what I'm thinking too, but I don't know how to find the problem.
I've checked and double checked each LED with my DMM in diode mode and they all light individually. I wish I had a LED tester where I could test a whole strip at a time.

Even though my replacement LED cutoffs are 3v is it possible that some other spec in them isn't the same as the originals and is throwing things off?

Another question. The top pin on the power connector on the PSU board is labeled 15.5v 16.5v but shows no voltage either in standby or when powered on. What is this pin for and shouldn't it show voltage?

thanks

[budm]

Re: Sharp LC-50LB370U Where to buy LED Strips?

The 15.5V circuit is not stuffed in your board.
Leave the Black probe on the chassis, red probe on one of the two black wire of the LED connector then turn the TV on while watching the meter to see if you see the Voltage jumps up for seconds or not, the turn off the TV and do the same on the other black wire of the LED connector, report the reading.
Those two black wires are the Cathode return foe each set of the LED strips, you have two LED driver control circuits.
+VLED1 (pin 1 of the LED connector) and +VLED2 (pin 12 of the connector) are tied together and fed by the Voltage booster circuit to feed the Anode of the LED strings.
Sharp PLTVEY701XAL5 Power Supply / LED Board for LC-50LB370U
http://www.shopjimmy.com/sharp-pltve...-50lb370u.htm#
Pictures provided by shopjimmy.

[mmartell]

Re: Sharp LC-50LB370U Where to buy LED Strips?

Bud your testing method has confused me. I have essentially the same set (lc50lb261u) with the same problem. Why would there be any voltage on the return wires if there is an open led in the string ?

I am having problems visualizing how these LEDs are wired together with the four wires off the driver...

I have a led tester. Proper test here is to disconnect the harness and put red to vled1+ and black to vled1- and repeat for vled2 circuit correct ?

[dick_barton]

Re: Sharp LC-50LB370U Where to buy LED Strips?

Looking at the circuit boards there are two led driver IC's.
IC8103 which drive one led string and IC8105 which drives the second set of led strings.

Led string 2 (VLED2) is connected between Pin 12 (+VLED2) and Pin 10+9+8 (-VLED2)
Led string 1 (VLED1) is connected to Pin 1 (+VLED1) and Pin 3+4+5 (-VLED1)
Pins 2, 6, 7 and 11 are No Connection.

[mmartell]

Re: Sharp LC-50LB370U Where to buy LED Strips?

Sure, and the + voltages are the red wires. So why is budm saying to measure using chassis ground and the black wires ?

[budm]

Re: Sharp LC-50LB370U Where to buy LED Strips?

I want to be 100% sure that we do not have Voltage on the return lines, I am sick and tired of getting the wrong DATA from so many threads.
The return lines of the LED strings are connected to those two IC's and then to GND, if IC's are not turned on then there will be no backlights, if the strings are OK then you will see Voltage at the return lines but there will be no backlights.