Help me please to fix my Led TV

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Disabled Account
Joined 2019
Hi,

I need a tip please. Don't know if it's the good section of the forum, sorry if not.

My 8 years Philips edge leds TV has no more image. At least there is one in the background on the dark screen: one can see it when very close from the screen.

Leds are around the screen (edge led TV) but I have sounds, no problems to lock on different channels. It's "just" the screen.

I thought about caps on the main smps board and I removed the back of the TV. Samwa capacitors have perfect flat top... all seems good, although I didn't measure yet their capacitance. Btw the main smps caps are 3x Long Life 68uF/450V.

Have you any experience of such thing. Could it be something else like active parts, leds, whatever ? I haven't removed the further metal back towards the screen, perhaps there are some smps lytics there ?

Have to said I had a little dark shadow area on an edge of the screen for some weeks, but still an image behind till yesterday. This area had also appeared on area to disseaper and comme back elsewhere till today ! That's why I think about the power supply without knowing if it's the main or perhaps a local cap elswhere (which I wouldn't fix in this last case).

Many thanks if any idea, well I can still listen to music on my hifi anyway :)
 
Hi diyiggy!

Generally, I would regard trying to repair LED TVs as not worth the time and effort as the manufacturers design them to be unservicable and hence disposable.

Eight years could even be regarded as a good innings for your Philips machine!

Having said that, a TV repair expert is now bound to pop up and prove me wrong! At least I'll have given your thread a nudge. :)
 
If you are still seeing a dark image close up, the problem *could be* just the backlight. We use a commercial flat panel (no longer manufactured) on a few of our sites and have had the backlights replaced on several units. You still may have to refer to factory service though. Whether it's worth it cost wise, you would have to get a quote.
 
Probably you have some burned led.
Google, led t.v bars, and you will see how they looks.
These are behind to lcd screen. Disasempling the lcd isn't an easy work.
You must be very careful! It is very fragile!
Led are in series, one is burned all are dark.
Use a battery to test one by one.
First of all!
Use google to find the cost of your bars.
May be cheaper to buy a new t. v.
 
Disabled Account
Joined 2019
Many thanks to all of you for these answers.

It's clear now than between the backlight or the leds around the edge, it will be too complicate and costly to me to investigate. The only thing I could do was to replace caps but they all looks in perfect condition on the main smps board where they suffer the most... and the one measured are ok (the fuse of my gear blowed after when measuring the capacitance of the main 68uF/450V despite it was switch off from one hour !

I didn't know there was also a backlight unit(s)but it makes sense as I can see just a little the image behind the very black curtain seen when looking at the display or the leds were in serie either... good too know!

Well, poor planet, 8 years is low regarding the geologic time and human pollution...

Thanks again to you for my non related hifi problem. Hoping now there are some cheap oleds less fragile (although i know obsolescence is a society disease we have to suffer for people having jobs... that's life !)

Good news is for several days I listen to more music.

kind regards,

diyiggy
 
On laptops it's common to replace backlight boards. On older ones there is a small transformer to generate the High Voltage for the CFL's. There should be some wires feeding the backlight leds, try to find them and measure if they actually have voltage. If they don't, You know the problem is in the PSU. There could be also a small board for controlling the backlight and on one of the pins there should be a control Voltage for controlling the brightness, If this part of the circuit is not working, You get a dark image. You need a service manual. You have replaced caps, but the problem can be elsewhere on the PSU. Regulators for example. If there are voltage markings on the PCB connectors, measure them. Disassembling the panel isn't easy and must be done in a clean room, like those where Hard-disks are assembled, or dust will catch between the panels. Have seen this often on Samsung TVs where You see a dirty area on the screen behind the front panel.
 
I am NOT interested in your Political and Social views.


Then don't buy into it.

FWIW, I'm not interested in your non-interest of political and social views (lower case unless they are more specific).

I happen to agree with diyiggy, and also with the The Stooges.

My LG TV decided to not turn on last week, and I was thinking the exact same thing. Built in redundancy, sign of the times etc.

And this was one of their better models, and after just 3 years. 12mo warranty. To their credit, LG have decided to fix it under concession and at their cost, but I think diyiggy's point remains, is valid, and is related to the thread.

Cheers,
HK
 
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I am NOT interested in your Political and Social views.

Not sure how your comment adds any value to the thread. You have anything constructive to say, because I don't think anyone cares what you are or aren't interested in.

Diyiggy, sounds like a backlight issue if you can still see the image, albeit faintly.

A lot of LCD TV models have a dedicated inverter board that runs the backlight, and Philips (and others) used to use LG manufactured panels iirc, so spares were quite freely available.

Get your model number off the label and have a look on places like ebay etc and see what spare parts are available. For as little as 10GBP or whatever your local currency may be, you might be able to get a replacement plug and play board. Might be worth a crack.

For illustration only (probably not for your TV) - LG PHILIPS LC260WX2 INVERTER PCB BOARD KLS-EE26-S MM14 MPCB182 | eBay

the fuse of my gear blowed after when measuring the capacitance of the main 68uF/450V despite it was switch off from one hour !

Just as a safety tip - capacitors can hold their charge for a very long time if there is no load across them. Before tinkering, please measure the DC voltage across the capacitor, starting with the highest scale (usually 600v) to ensure that they are discharged.

Capacitors inside HV equipment (such as TVs) can have a deadly bite..

Good luck with the TV!
 
Funny thing is that diyiggy´s comment was quite light and unobtrusive, not as if he were yelling his lungs off standing on a soapbox or constantly deviating thread focus.
On the contrary, it was a comment on (the frequency of) a failure.

That said, I have the opposite view :eek:

I think 8 years service life for a *wonderful* piece of equipment, tecnologically advanced and very complex, made by the Millions and for such a low price (considering what it involves), is truly a "Modern Marvel"(as defined by History Channel :) ) and we should be happy for having it available.

Again contradicting :eek: , I don´t see "planned obsolescence" here, 8 years of good service are way beyond any realistic Warranty time.

And failure is most probably repairable as mentioned above, it´s just that this TV is *so* cheap thanks to massive automated production, that fully replacing it by a new one is economically possible, compared to Service Tech man hour cost.

But that´s nothing evil, quite the contrary. :p
 
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Disabled Account
Joined 2019
Funny House

Thank you guys for the help provided and nice posts.

Well I'm afraid to have not enough skill to dive deeper than the first onion ring which is the plastic back cover. there are two boards only after the cover, the smps board and the massive tinny smps parts I/O board (ethernet, antenna, YUV, etc).

But I will try as I have nothing to loose thanks the good advices and links. It is surely the back light system but it's after the second metallic onion ring which seems complicate to remove with many metallic clips.

Anyway, lesson learned, next TV will be cheaper to save for the further next one and because my mother doesn't look at Marvel movies but mainly historical or scientifical channels and sometimes food channels, so no needs of complicate enhancer codecs. (apologize to Art M about mother's life you certainly don't care either :eek: ... all those onions makes me cry).

best regards to ALL of you
 
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Disabled Account
Joined 2019
Philips 40PFL6636H/12

Hi again,

I have found many valuable Youtubes on how to disassemble a Led TV thanks to the "key words" provided in the thread. :) . In fact few boards : a smps, the main AV boards and the famous backlight inverter board hiden on the front side of the TV.

The second layer I was talking about is in fact the main aluminium body and the back leds and backlight inverter board is in fact on the opposite side, i.e. towards the display panel side. So one has to remove the edge, the screen, the delicate transparent film... trying to avoid dust as said in this thread.

Thanks to the inputs here one indeed can find on ebay some inverter board, not expensive, worth a try. But not so many boards avaliable. 8 eight year is for sure a long time for such consumer products as already mentioned.

One has to have skill to find the reference on the net. If Ebay is not good enough then Tobao is perhaps the place if one can speak chinese.

There are also Youtubes on how to swap one led only instead a complete leds strip. But again one can also buy those leds strip.

Sourcing those parts is tricky. It is not like to choose a part at Mouser or Digikey !

Your inputs helped a lot :)
 
Disabled Account
Joined 2019
thanks

Hi,

Exactly this one, thanks ! Yes this is the Power supply board: caps seem good on mine : capacitance value are ok ! Although I have sound and can swap between channels ! Just a dark ground with the image "behind" you can see when very close to the board, so it's not a smps failure but if the inverter board is embeded on it and if so your link is just wonderfull, didn't find it myself despite I entered the ref ?!

Seems everyone agree it should be the inverter board. One can buzz also each led to see if they are broken or not as they are in serie for the few I understood and the videos seen. My idea is just to swap a board if not expensive or to see if it is a or the strip if a standalone parts.

I have yet to futher dissasemble the TV to see the leds and the backlight inverter board. This issue often happens from what I readed after the tips here and some diyers try to fix it themselves. Working cost will be the same than a new TV today for the screen size I have (40").
 
Probably you have some burned led.
Google, led t.v bars, and you will see how they looks.
These are behind to lcd screen. Disasempling the lcd isn't an easy work.
You must be very careful! It is very fragile!
Led are in series, one is burned all are dark.
Use a battery to test one by one.
First of all!
Use google to find the cost of your bars.
May be cheaper to buy a new t. v.

If you find one burned LED just bridge it with a resistor.
Saves stripping out the lot for the sake of one duff LED.
The LED's should all have same resistance using a diode checker on your DMM.
The bad one is most likely open circuit.
 
Hi,

I need a tip please. Don't know if it's the good section of the forum, sorry if not.

My 8 years Philips edge leds TV has no more image. At least there is one in the background on the dark screen: one can see it when very close from the screen.

Leds are around the screen (edge led TV) but I have sounds, no problems to lock on different channels. It's "just" the screen.

I thought about caps on the main smps board and I removed the back of the TV. Samwa capacitors have perfect flat top... all seems good, although I didn't measure yet their capacitance. Btw the main smps caps are 3x Long Life 68uF/450V.

Have you any experience of such thing. Could it be something else like active parts, leds, whatever ? I haven't removed the further metal back towards the screen, perhaps there are some smps lytics there ?

Have to said I had a little dark shadow area on an edge of the screen for some weeks, but still an image behind till yesterday. This area had also appeared on area to disseaper and comme back elsewhere till today ! That's why I think about the power supply without knowing if it's the main or perhaps a local cap elswhere (which I wouldn't fix in this last case).

Many thanks if any idea, well I can still listen to music on my hifi anyway :)

Most likely you have some LEDs open, sadly you must to disassemble the display, check them one by one with a low voltage PSU and change the bad ones.

Maybe youtube has an instructive video which can guide you through the process.

Some tips

i) The LCD panel is extremely delicate, put a piece of about 4mm plywood (or similar) under it to not curve it. If your display is e.g. 40" the piece of plywood must be a little larger, say 42".

ii) Take the plastic sheets (Under the LCD panel) all together with some adhesive tape in one or two corners, so the order does not change and be cautious because big plastic areas can create big electric charges and high voltages in the order of tens of KV, do not worry it won't kill you, but it hurts, believe me.

iii) Remove the white paper, which is normally fixed with plastic clamps and now you can see the LEDs.

iv) With a low voltage PSU (say 12V) and a 1K series resistor you can search for defective LEDs, carefully remove the plastic optic and change the respective LED.

If you live in the first world maybe you can buy all the LED strings and put them all new, easier but costly.

v) Carefully glue the plastic optics again, silicone adhesive works very well. Warn you that you must check again one by one (with plastic sheets on) the diffused light of all LEDs. Worst case you must re-glue a couple of plastic optics until the light cover the whole display area more or less uniformly.

vi) Reassemble the display panel, and be gentle with LCD panel edges.

vii) If everything goes right, put the backlight intensity on 50% and enjoy.


Good luck!
 
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