LG 42PJ350 Starts, Shuts down, won't restart

[Mikeyboy2007]

Re: LG 42PJ350 Starts, Shuts down, won't restart

i found it right after posting that, how do i test this though ? the r927 22ohm resistor
& r929 22ohm resistor are testing ok at 22.3 and i will need to remove a leg from diode D304 to test that but never tested a voltage regulator before ?

[vinceroger69]

Re: LG 42PJ350 Starts, Shuts down, won't restart

neither have i maybe tom or budm maybe able to advise? can you find a data sheet for it and post a link in advance to be honest if its a cheap part just replace it.
Now you have found the regulator try resoldering all the joints even if they look good and test the set you have nothing to loose check that diode first though.

[vinceroger69]

Re: LG 42PJ350 Starts, Shuts down, won't restart

http://www.ebay.co.uk/itm/ICE3BR1565...item1e967ea16a
There not a bad price maybe also check rs components as they have free postage offer on now.

[dkneyle]

Re: LG 42PJ350 Starts, Shuts down, won't restart

I think you've worked out that the regulator is the 6 legged device. Can't really be tested. Yes you can pick them up from Taiwan via E-Bay for next to nothing. You replace it and see if things get better!

[Mikeyboy2007]

Re: LG 42PJ350 Starts, Shuts down, won't restart

hi guys i put fresh solder round the legs of the voltage regulator and tv has now been on for around 2 hours. think it may just have been a dry solder joint then.

[dkneyle]

Re: LG 42PJ350 Starts, Shuts down, won't restart

Yes, if I had my time over again with the set I fixed I think this would be what I'd go to first. Think about it. This device gets hot; that's why it's on a heatsink. It gets hot enough that the solder melts away from the solder pad. Classic dry joint problem. Hit it with a hot iron and a fresh bit of solder and bingo, fixed!

[ryanfan03]

Re: LG 42PJ350 Starts, Shuts down, won't restart

I have the same tv in my TO-DO pile. The guy I got it from tried the power board repair (crudely I might add) but that didnt work. I traced the problem to the Y SUS board and a few components including a transistor and a resistor. I havent had time lately to replace or check further. Anyone else have a similar experience?

[Mikeyboy2007]

Re: LG 42PJ350 Starts, Shuts down, won't restart

Ok so tv stayed on for 8 hours or so then i decided to turn it off... i left it for 3 hours then switched back on and after a few minutes it shut itself off and when trying to startup it went through the clicking crap.... i am going to change the voltage regulator and see if that helps any.

[odheng77]

Re: LG 42PJ350 Starts, Shuts down, won't restart

hi .. I am from Indonesia ..
I also have a lg tv 42pj350 and suffered the same damage . he does not want to start . only the standby LED lights are flashing .
whether the same damage lies in 3BR1565JF ?

[Mikeyboy2007]

Re: LG 42PJ350 Starts, Shuts down, won't restart

i changed the voltage regulator 3BR1565JF and it worked for a few days there but now its back to square one ? could something be knocking this out ? any help is welcomed

[dkneyle]

Re: LG 42PJ350 Starts, Shuts down, won't restart

check that any fast switching diodes used as dampners are ok

[Amraks]

Re: LG 42PJ350 Starts, Shuts down, won't restart

Back Again
Tv Was running fine, now its doing it again just now.

I suspect the chip has gone again will order 2 this time.

[dkneyle]

Re: LG 42PJ350 Starts, Shuts down, won't restart

Tell us if replacing the chip gets you in business again. It does seem like the regulating chip is working too hard or something else causes them to fail. Have a good look at the diodes that are used to snub out high frequency oscillations and the such like.

[Amraks]

Re: LG 42PJ350 Starts, Shuts down, won't restart

Hey back again I manage to get 3 - 4 hours out of the set before it starts the cycle of clicking on and off.

I have replaced the voltage regulatory also run individual wires to test that its not cold solder joints.

I am suspecting the 5w22O Resistors are bad this time, I will let you know what I come up with.

[lesnajair]

Re: LG 42PJ350 Starts, Shuts down, won't restart

These blooming PJ series!! I've got a PJ650 and it has the same issue. Replaced the voltage IC managed to get the red led to go blue, LG logo and a channel id logo then went straight back to square one clicking etc. with red slow flashing red led. Grrr! Managed to get a new psu board but worried it might get fried!!

[dkneyle]

Re: LG 42PJ350 Starts, Shuts down, won't restart

There certainly appears to be a design fault that is causing the power IC to overload and fail. I don't have the board any longer to look at so I don't know what more advice to give. Those power resistors are known to be problematic in other SMPS. What value do they measure? Do they look physically stressed?

[Amraks]

Re: LG 42PJ350 Starts, Shuts down, won't restart

22.04 to 22.05 even the new resistors tested the same.

Seems like the set got worse after sitting longer this time as it a instant failure.

[Amraks]

Re: LG 42PJ350 Starts, Shuts down, won't restart

You will be happy to know dkneyle after a few years I got around to working on this tv again and it working.
6 resistors R08 - R13

It is safe to bridge pc101 on the cold side to test the voltage drop on them resistors.
you should see it straight away when you test voltage on individual resistors. I noticed it mainly on R110 it was lower than the others.

[dkneyle]

Re: LG 42PJ350 Starts, Shuts down, won't restart

G'Day Amtraks. Great to see a story finally resolved! (I too drift in and out of this hobby depending upon motivation.)

[Amraks]

Re: LG 42PJ350 Starts, Shuts down, won't restart

Its good its not taking up space now..
now I got the 27 inch tv for the bedroom I was using while this one was down to get rid of lol
I don't get many tv repairs coming in just a few screen replacement jobs and just bought a microscope for micro soldering hoping to do some ps4 port repairs instead of turning them down..
if you still have this tv I can post you some of them resistors I got 15000 of them as I had to buy 3 reels lol.