Panasonic TH-L50EM6A LED LCD - no power

[tw2005]

Thought I'd have another go at a Panasonic LCD Panasonic TH-L50EM6A LED LCD.

2013 series TV, fairly basic model, not a smart TV nor does it have any network capability which is pretty disappointing for the model year.

Yet from what I read a $1300 first released, dropping to around $800 AUD

Symptoms are no power, no standby LED.

To be honest I have pretty crap luck with LCD TVs and I was expecting this to be a failed A-board.

Anyway, pulling the back off, probing I find no voltage going to the A-board.

Fuse is fine on the P-board.

Check IC7503 (C0DBAYY01599) LV5980MC SANYO Step-down Switching Regulator , find the output was not shorted but pin 7 Vin short to ground.

Looking at the schematic there's a number of components that could be short. Both D7408 and 7409 are showing short.

So it was a toss up between those and the IC, removed D7408 and incredibly that was it, short gone. Lucky guess.

The diodes (B0JDSG000010) are marked Q165A = RBQ10B65A by ROHM 65V 10amp schottky

The package is SC-63 or TO252, DPak.

So I've wedged a RF1501 of a SC board just for testing but will have to get the right package as it's to tight and close to the other tracks.

And that's that. Working with only 2300 odd hours on it.

Picture's not too bad, still prefer Plasma but this uses about a third of the power.

Something else I noticed too, C7422 which is a 680uF 35V cap on this version TNPA5807UE is a F@!#ing Jamicon! This is very similar to my last Panasonic LCD which kept burning out Fets for the backlight. It too had a random crap brand Cap which was the cause of that fault. The rest were Rubycon.

This board , exactly the same , all Rubycon except this random Jamicon and it sits on the 24V line and the two FETs.

Yet I look at a TNPA5807 on Shopjimmy and some UK boards on Ebay and it's a nice Rubycon.

Conspiracy theory?

I think I should change it out.

[JeffJ]

Re: Panasonic TH-L50EM6A LED LCD - no power

I do a lot of Settop box repairs, and they are also designed to fail like this. All top quality caps except one shitty Capxon or Jamicon cap some where in the Power circuit that will fail.

I have seen this so often that its the "norm" and I am 100% convinced its on purpose to put a life span on the electronics so the consumer has to lease rent or buy a new set top box every 2 years or so just after its paid off or their contract ends. Then given that most providers here charge WAY too much for a settop box, they hook people in to another rent to own or contract to get the new box at an extreme discount or free and the cycle continues.

They also like to put the shitty cap on a power rail that is very close to the rails output so any spikes slowly damage the junk cap, and its also crammed by something that gets hot as hell and its a 85C cap too of course. *rolls eyes* Surprising eh?

6.3v caps on a 5v rail, always always leak in this case. Makes me mad, replace with a 10v good panny or ruby and the device never has to be serviced again.

Bottom line F**Kin' shady shit

[tw2005]

Re: Panasonic TH-L50EM6A LED LCD - no power

I do a lot of Settop box repairs, and they are also designed to fail like this. All top quality caps except one shitty Capxon or Jamicon cap some where in the Power circuit that will fail.

I have seen this so often that its the "norm" and I am 100% convinced its on purpose to put a life span on the electronics so the consumer has to lease rent or buy a new set top box every 2 years or so just after its paid off or their contract ends. Then given that most providers here charge WAY too much for a settop box, they hook people in to another rent to own or contract to get the new box at an extreme discount or free and the cycle continues.

They also like to put the shitty cap on a power rail that is very close to the rails output so any spikes slowly damage the junk cap, and its also crammed by something that gets hot as hell and its a 85C cap too of course. *rolls eyes* Surprising eh?

6.3v caps on a 5v rail, always always leak in this case. Makes me mad, replace with a 10v good panny or ruby and the device never has to be serviced again.

Bottom line F**Kin' shady shit

I think it's weird. Obviously they must produce the boards in more than one factory. At least this is 105c last one had 85c that was a th-L19X10AK.

[tw2005]

Re: Panasonic TH-L50EM6A LED LCD - no power

Here's a few versions, the first two are the same. First being my version and the second is the same but UK, then others

[JeffJ]

Re: Panasonic TH-L50EM6A LED LCD - no power

Different manufacturers yes.

My theory is, the manufacturing facility swap in what they can to save, to maximize profit possibly?

If it were up to the engineers who designed the circuit, you would think they would decline to use inferior parts when the rest of their design does not use them, especially since other boards are getting the better quality parts.

[Alastair E]

Re: Panasonic TH-L50EM6A LED LCD - no power

Design Life, 18 months.

[tw2005]

Re: Panasonic TH-L50EM6A LED LCD - no power

Design Life, 18 months.

could be close, I suspect this was purchased 2014, did about 2365hrs , 779 cycles.

Average on time 3 hrs assuming it was on once a day , a little over 2 years of daily use.