LG TV Board Issue

[ScorpioMan86]

Hi Guys,

This is my first attempt at tv repair, i usually just do basic things like cap replacement on lcd monitors so my knowledge is not that much.

After opening the to measure standby voltage as there was no light in front of the tv, the board is eax55357701/32 as per pic and there's a burned trace to from what i assume is a transformer ?

My question then is whether i should get a board from ebay or this trace can be manually redone ? i.e. solder a wire from the leg of the transformer but to which point (s)

Thanks

[jondoe]

Re: LG TV Board Issue

That looks easy enough to put on some bodge wires, but you need to be sure that whatever caused the issue won't burn it out again when you power it up. Don't skimp on the size of the wire, those are some meaty traces.

[ScorpioMan86]

Re: LG TV Board Issue

That looks easy enough to put on some bodge wires, but you need to be sure that whatever caused the issue won't burn it out again when you power it up. Don't skimp on the size of the wire, those are some meaty traces.

Thanks for the response jondoe, i am just not sure to which part the wire(s) needs to go to from the transformer leg

[dick_barton]

Re: LG TV Board Issue

The track appears to have vapourised so whatever caused that needs to be looked at otherwise replacing it with wire is not going to solve the reason it happened in the first place.
Was the power supply placed on the back of the panel or slipped down on to the panel and shorted when the set was switched on?

[dick_barton]

Re: LG TV Board Issue

What's the model number of the set?

[ScorpioMan86]

Re: LG TV Board Issue

The track appears to have vapourised so whatever caused that needs to be looked at otherwise replacing it with wire is not going to solve the reason it happened in the first place.
Was the power supply placed on the back of the panel or slipped down on to the panel and shorted when the set was switched on?

Hi dick_barton

According to the client the tv fell off while on from the wall mount it was attached to so i would naturally assume it did short

[ScorpioMan86]

Re: LG TV Board Issue

What's the model number of the set?

Model number is 42LH22R -AFB

[jondoe]

Re: LG TV Board Issue

Thanks for the response jondoe, i am just not sure to which part the wire(s) needs to go to from the transformer leg

I'd scratch off the lacquer and attach the wires directly to some "good" track material, just for the purposes of testing.

[diif]

Re: LG TV Board Issue

I'd scratch off the lacquer and attach the wires directly to some "good" track material, just for the purposes of testing.

You don't need to scratch anything. Just attach the wires to the two points that are already soldered where they come through the board.

I would also resolder the bottom connection.

[jondoe]

Re: LG TV Board Issue

You don't need to scratch anything. Just attach the wires to the two points that are already soldered where they come through the board.

Horses for courses

[dick_barton]

Re: LG TV Board Issue

I would do as diff says and use multi-stranded insulated copper wire and attached at the nearest adequate solder point at either end of the break.

[vinceroger69]

Re: LG TV Board Issue

Hi dick_barton

According to the client the tv fell off while on from the wall mount it was attached to so i would naturally assume it did short

i hope the lcd panel is ok after a fall like this i wouldnt be suprised if its damaged

[ScorpioMan86]

Re: LG TV Board Issue

You don't need to scratch anything. Just attach the wires to the two points that are already soldered where they come through the board.

I would also resolder the bottom connection.

Hi Diff,

Thank you for the suggestion, i did this, and replaced the fuse that didn't have continuity, i however am not sure if the fuse i used is of the same rating, because i have power for 5 seconds and it goes back to standby, i am going to pickup the proper fuse today and will see how that goes.

[ScorpioMan86]

Re: LG TV Board Issue

i hope the lcd panel is ok after a fall like this i wouldnt be suprised if its damaged

Luckily the panel seems fine still, for the 5 seconds the display comes on lol, will post an update after further tests

[mmartell]

Re: LG TV Board Issue

The fuse is not likely to turn the power off after 5 seconds unless it blows each time. You have other problems.

[ScorpioMan86]

Re: LG TV Board Issue

The fuse is not likely to turn the power off after 5 seconds unless it blows each time. You have other problems.

Hi mmartell, you are correct the fuse doesnt blow each time , i am however lost as to what the issue can be now, i pulled some light tubes from a 27" monitor and plugged them onto the board but they also switch off after 5 seconds so i assume the lights tubes are correct ?

i am not sure what to test now

[Dumah Brazorf]

Re: LG TV Board Issue

Reflow all the soldering points you can, expecially of the heavy components 'cause they have kicked the board in the impact and may have cracked the joints.
Clean your iron, your soldering is pretty ugly.

[syaoran123]

Re: LG TV Board Issue

That joint EY47 on RHS of photo looks like cracked solder.

[Andrew F. Ali]

Re: LG TV Board Issue

Maybe the Monitor is sensing 'No Signal' and shutting off to Sd-By.