LG 42LV5400 powers on, no video, no sound

[Sevenqi]

Re: LG 42LV5400 powers on, no video, no sound

I had the same model and same problem, what I did was to reflow the main processor on the main board with heat gun, problem fixed.

[drkthundr]

Re: LG 42LV5400 powers on, no video, no sound

I will look into that.

[Dgtech]

Re: LG 42LV5400 powers on, no video, no sound

I'm dealing with the same issue here https://www.badcaps.net/forum/showth...ighlight=Ic602

Its great to see that my reading are very similar to other people. I'm stuck on why that Ic602 is not doing its job. I'm not sure though.

[drkthundr]

Re: LG 42LV5400 powers on, no video, no sound

I have been wondering that as well.

[Dgtech]

Re: LG 42LV5400 powers on, no video, no sound

I sold mine today (55 inch - LG 55LV5400) in non working state for $100. Lets keep the money moving - no time to stop.

[drkthundr]

Re: LG 42LV5400 powers on, no video, no sound

I'm going to keep at for a while longer. I like a challenge.

[ScottKnight]

Re: LG 42LV5400 powers on, no video, no sound

Joined because of this thread since I have a 55LV5400 that is doing exactly the same thing. I have been through everything drkthundr and dgtech have as well as two trips through the oven. Possible for that IC602 to go bad?

[Dgtech]

Re: LG 42LV5400 powers on, no video, no sound

Check the thread here for both the service manual and the training manual PDF's.

https://www.badcaps.net/forum/showth...636#post737636



I think the mainboard needs replaced as others have done to fix the problem.

[Dgtech]

Re: LG 42LV5400 powers on, no video, no sound

Joined because of this thread since I have a 55LV5400 that is doing exactly the same thing. I have been through everything drkthundr and dgtech have as well as two trips through the oven. Possible for that IC602 to go bad?

I tried to look up the datasheet for that IC602 to try to see what turns that pin 10 off but I got nowhere with it. After reading mostly all of the posts in several threads on this set, I'm convinced that if the board can't be reflowed by heatgun or oven method, just replace the mainboard.

Search for the EAX or EBR or EBT # on your mainboard. I saw one this morning going for 127 from canada.

[drkthundr]

Re: LG 42LV5400 powers on, no video, no sound

I touched up q504 and the corresponding resistors around it, Plus i put foil tape around and on the backside of the board for Ic101. I squeezed some no clean flux around and under the IC and took my hot air desoldering device to it and heated it up and let it cool down. Removed foil tape and put the board back in and tv turned on. Success but discovered the screen has lines in it caused by the screen. They are fine lines but they are there, so cant sell that way. NNNNooooooo Guess i will be parting this one out and selling boards on ebay. sometimes you win some some, times you loose some, and sometimes you have to take what you get and move on.

[mrjiffy6]

Re: LG 42LV5400 powers on, no video, no sound

As well as many others, I fixed this problem by reflowing the whole board in a oven and it's been working perfectly since then.

When I prepared the board for reflowing, I noticed a small curve on the heatsink so it wouldn't even touch the main IC, making the heatsink completely useless. So before mounting it back, I flattened the heatsink surface and put some thermal paste where the IC sits on.

My guess is indeed the BGA solder balls of the main IC cracked slowly through thermal cycling, which seems to be a well known problem of the BGA ball packages of ICs. It might also explains the slow degradation of the TV performances until it wouldn't even "boot" at all.

[minho_newt]

Re: LG 42LV5400 powers on, no video, no sound

Yep, I will vouch for the main board reflow. My LG 42LV5400 had no picture/no sound, the PS was good, all caps okay (even though I changed two of them anyway).

In the end, I put the board in the oven at 385-395F for ~12 minutes. Reconnected everything and BAM...the darn TV works again. I don't know if this is a long term fix, probably not, as you are still stuck with that crappy lead-free solder. The perfect solution would be to do a proper reball with leaded solder of the main IC.

[mrjiffy6]

Re: LG 42LV5400 powers on, no video, no sound

Well, guess what? It is not a long term fix

The picture started to look crappy again about 3 months ago. I'm waiting until it "dies" again to reflow it once more!

[neilc6]

Re: LG 42LV5400 powers on, no video, no sound

If you search the main board part number on ebay, you will find some sellers that do reballing for around $100 USD.

[Mendykremodel]

Re: LG 42LV5400 powers on, no video, no sound

Hi, i have an lg 50pk750. Im experiencing the same thing. The tv turns on, the main blue light is reactive to remote and manual button pushes, but no menu/vol bar, no sound and no picture. The lcd screen is lit and looks normal, even lights up for a moment on start up. I replaced what looked like a bad capacitor on the power supply board with no change. After reading the thread, im thinking the problem is somewhere on the main board instead. Am i correct? Thanks in advance