LG 50PJ250 - 3 click relay sound

[angel-boy]

LG 50PJ250 - 3 click relay sound , wont start up, the client say that after some time is power up.

-i see on ebay a repair kit, but the fuse is good ( if ICE3BR1565JF was bad , the fuse should burn )

power board code - eax61397101/11

any ideea ?

[comptek]

Re: LG 50PJ250 - 3 click relay sound

check voltage regulator and diode out of circuit and the 2 big 5w resistors top right

[angel-boy]

Re: LG 50PJ250 - 3 click relay sound

what diode and regulator ? draw on picture please

[Electronic Handyman]

Re: LG 50PJ250 - 3 click relay sound

Looking at that board it sure has a lot of hot spots that means parts like the electrolytic capacitors are probably bad.Check them closely especially the ones near the heatsinks. What I usually do with those boards is go over all the soldering points bec usually I find several bad connections.Especially at the transistors and hot spots, go over then very closely and I bet you'll find several bad connections.

It depends if you've capacitors on hand but I bet some of those are leaking or no good.Usually to rebuild such boards I change all the electrolytic capacitors accept the big ones that are like 400v etc.When changing them I replace them with higher voltage caps.For example you probably have some that 330UF 10V or 16V or 25V or 35V .So if it was a 16v I'd upgrade it to 25v or 35v that's if I could find ones that would fit into the circuit.Remember to purchase good quality low ESR CAPS.Always test the new caps before you install them.Only do one at a time and make up a chart with sat C209 = 330UF 16V and list what your replacement was.

Believe it not even brand new boards can have weak or faulty capacitors and I've for many bad connections on brand new boards too.Those board designs that use so many heat sinks get darn hot and if the caps are so close to such heat or it already has bad soldering you will end up with worse connections or failing parts.I believe on those boards you've diodes and transistors on those strips of heatsinks. Check all the plug in connector pins too bec I've seen some with several bad connections, don't forget to check the grounds.

Anyways I usually go by my gut and just looking at that pic made me think bad connections and probably atleast one bad cap but some other part might be gone too but usually if diodes or transistors fail they short out and said that the fuse wasn't blow.So you said that no fuse is blown but be sure to check that board closely bec usually there is a 5v fuse and atleast one other higher voltage fuse.

If it's a repair for me or a friend I will basically change every cap especially on boards like that but rem usually the bigger higher voltage caps on psu's don't fail.You may notice more then one type of repair kit online for the same board I prefer the ones that include the all or most of the known caps that fail, plus any regulators or chips etc.

It can take hrs to rebuild and replace parts on such boards but you will notice that the overall set will work better.The last one I did for a buddy he said the set is working like when he first took it out of the box.Again that's bec I soldered the connections and I replaced 95% of the capacitors, plus upgraded the caps too.Remember if the cap is rared for higher voltage it can handle more voltage load especially if it's a proper low ESR cap.


Anyways I just wanted to give you some feed back and insight in how I rebuild the boards but note sometimes it's best just to look up the boards part numbers and look online for a replacement.One last note remember that if the manufacture used a lower grade cap on the old board those same low grade caps are probably in the used or new replacement boards.Sometimes you can find a board that's a newer version that has better parts in it.Sometimes the same board is also used in different models and bigger screen sets that might be a board that works in several models and is build better too.

[comptek]

Re: LG 50PJ250 - 3 click relay sound

what diode and regulator ? draw on picture please

marked them for you
on the voltage regulator check for shorts on meter set to diode mode

on the diode remove one leg and check with meter on diode mode

[comptek]

Re: LG 50PJ250 - 3 click relay sound

as it seems it will start after a while check caps with esr meter
study solder side for dry joints

[angel-boy]

Re: LG 50PJ250 - 3 click relay sound

the diode is not shorted. I will check de caps

[comptek]

Re: LG 50PJ250 - 3 click relay sound

the diode is not shorted. I will check de caps

voltage reg is that ok