Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

Well... this process got me somewhere.

I've tested the TV... yesterday ot worked for 3 hours.
Today... 15 minutes. And now backlight it is constantly off!

Well... this could also mean two things:
1. my soldering skills are like 8year-old-kids'...
2. some faulty LED finally broke...

I would like it to be the 2nd one.

I'll open it again tomorrow.

Oh... yeah... status: sound is on... picture is on... backlight is off.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

Here are the photos of exposed LED strips, one connector to the strip (all looked the same and all looked ok), middle connector with four lines, and connector to the PSU (I did not resolder this one... did not think I should).

[vinceroger69]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

while the sets apart can you test each led lights up you can use your multimeter or a 3v battery there are some really good guides on youtube.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

while the sets apart can you test each led lights up you can use your multimeter or a 3v battery there are some really good guides on youtube.

That is what I was waiting for. When I had backlights than all the LEDs were working. Now when I have no backlight that means what I can pinpoint the faulty one. It will be totally disappointing if I find out that my soldering made a short circuit somewhere... I'll report what I find.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

I wanted to open my TV today and check LEDs... but when I powered it on... it still works.
The LEDs are still working.

[vinceroger69]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

i hate faults like this some sets do work for a while whist cold/cool but as things warm up they expand and cause issues etc its just finding the faulty joint/part.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

Today it worked without any problems for 8 hours. And I switched it off...

[CapLeaker]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

Today it worked without any problems for 8 hours. And I switched it off...

Hopefully it stays that way.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

Hopefully it stays that way.

I thought it finally broke down. That way I could find what was wrong with it... but no... still works.
Yestarday it worked for 6 hours without any problem.

[ReeceyBurger123]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

So thats with the Led connectors bridged over ?

[vinceroger69]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

So thats with the Led connectors bridged over ?

i was wondering that to as none of the pictures show the bridge wires some people have got away with just adding fresh solder to the pcb contacts (side strip) but as you say bridging them is the best way im sure you have a picture somewhere showing this method.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

So thats with the Led connectors bridged over ?

Yes. All LED strips bridged. After bridging I could not get it to work one whole day. And thought that that was it.
But now it works.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

i was wondering that to as none of the pictures show the bridge wires some people have got away with just adding fresh solder to the pcb contacts (side strip) but as you say bridging them is the best way im sure you have a picture somewhere showing this method.

No... I did not make any photo after bridging. I made 10cm long isolated wires and soldered those between led strips and board. I also made connection at that 4pin connector. Upper two are connected and lower two also. I bridged that connector with two wires. I'm now waiting for it to stop working. I'll make photos when I open it again.

[vinceroger69]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

thats the best way to bridge them so it should work fine but as you say until it fails again its hard to fault find is the tv fully rebuilt up with back on etc just incase its a heat related fault.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

I opened it. Fanally!
And checked connections. Everything ok.
I've soldered wires to bridge connections with the strip. I've made those longer just to ensure that I do not have to resoledr if I need to remove some strip.

I have LED strips with 9 LEDs. I've connected each strip to 24V PSU.
All worked! But one stripe had a bit faint light and one LED that did not work!
Then I removed a lense from the LED and now I cannot identify the type.
Photos uploaded: connection with wires to LED strips, connection in the middle of printed board, LED with lense removed, faulty LED.
Please help me with identification of this faulty LED!
Dimensions are as of 3528... 3.5mm (with soldered ends) and 2.8mm.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

Conclusion of this whole thing: operation successcu! Patient dead!

I've managed to remove old LED, replaced it.

But at the end I realised that I forgot those plastic central suports for the screen... and reopened it... and than cracked the edge of the screen while closing the box.

Well... it was fun. I've made a hot air station for this. Learned alot. Thank you all for the help!

[dick_barton]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

I doubt you'll make the same mistake twice.

[bbccbb]

Re: Sharp LCD LED TV LC-39LD145V [C] - Vestel 17IPS20S, problem with backlight

I doubt you'll make the same mistake twice.

Not on this TV.