LG 55LF 5800 no video,no sound or backlight

[Davi.p]

don't judge soon, often chip pins offers bad connection to probes, unpower the board, scrape pins a little with screwdriver, then test it again...

[waybel]

ok

[nomoresonys]

Heating the bga with hairdryer doesn't always get test results so it's not greatly reliable. A diy reflow done PROPERLY shouldn't hurt at all, It's a different process and is not done with a hairdryer: A diy reflow, involves getting the solder under the chip melted so it can reattach to the chip. Pretty straight forward, there's some good how to videos on youtube. Must be careful not to overheat or it will kill the chip, not enough heat and nothing bad will happen, it just won't work is all. They recommend gradual heating then gradually take heat away so as not to thermal shock the chip. Using a temperature gauge would be advised. Need to be extra careful not to blow away or lose any of those little components nearby such as those pesky little mlc caps. Here's a rough idea of the procedure using minimal tools. If one must use a heatgun be very careful with the temps, a lot of them were not meant for the lower temps needed for this kind of work, hot air stations are a much better tool for the job.

[nomoresonys]

Example here on a graphics chip, same principal: https://www.youtube.com/watch?v=FU84qGSdE-s

[nomoresonys]

Basically a diy reflow done correctly does no harm, so I do it after doing all the usual
mainboard tests for shorts and voltage etc. and if find no other obvious problems with the board.

[Storyteller12]

A reflow on this chip will not work. These boards need the processor replaced.
I believe Nicks TV has done a yt video on these models and the processor problems.

[waybel]

Heating the bga with hairdryer doesn't always get test results so it's not greatly reliable. A diy reflow done PROPERLY shouldn't hurt at all, It's a different process and is not done with a hairdryer: A diy reflow, involves getting the solder under the chip melted so it can reattach to the chip. Pretty straight forward, there's some good how to videos on youtube. Must be careful not to overheat or it will kill the chip, not enough heat and nothing bad will happen, it just won't work is all. They recommend gradual heating then gradually take heat away so as not to thermal shock the chip. Using a temperature gauge would be advised. Need to be extra careful not to blow away or lose any of those little components nearby such as those pesky little mlc caps. Here's a rough idea of the procedure using minimal tools. If one must use a heatgun be very careful with the temps, a lot of them were not meant for the lower temps needed for this kind of work, hot air stations are a much better tool for the job.

I used a hot air station but no luck

[waybel]

Could someone tell me what main board will fit this tv.The one that is in it reads EAX65610207 EBT63774501 .The LG site says it should be EBT63838802 .Another site said EAX65610206 Some of these boards are dirt cheap but i don't want to buy one then it doesn't work.Why do i have to keep putting the image verification every time i ask a question on here?

[lotas]

Could someone tell me what main board will fit this tv.The one that is in it reads EAX65610207 EBT63774501 .The LG site says it should be EBT63838802 .Another site said EAX65610206 Some of these boards are dirt cheap but i don't want to buy one then it doesn't work.Why do i have to keep putting the image verification every time i ask a question on here?

EAXxxxxxx is the PCB number, different models are assembled on it, look for a paper tag with the number EBTxxxxxx, this will be for your model.

[waybel]

EAXxxxxxx is the PCB number, different models are assembled on it, look for a paper tag with the number EBTxxxxxx, this will be for your model.

Ok well then i guess LG changed the number from the old board or someone changed this board.This board is a EBT63838801 and the LG site says the correct board is a EBT63838802.Is it possible that more than 1 board will work?

[lotas]

Most likely a new modification (improvement, modification, with new software...), since the old ones are no longer produced, the difference is one, this is also yours...
https://www.shopjimmy.com/lg-ebt6383...fdGG9wttWjRHAU

[nomoresonys]

A reflow on this chip will not work. These boards need the processor replaced.
I believe Nicks TV has done a yt video on these models and the processor problems.

Well that's a new one on me but if Nick said so then I don't doubt it at all.

[waybel]

yes, but if you follow the pin 4 rail you will finnd easy point to separated the pin. post clear photo on the area of the PIN 4 rail.. we dont want you harm the MICOM chip

Are we still going to try this?

[Diah]

Are we still going to try this?

ob to you... but you need to read all posts from my '#54 to #57.. MICOM DIY an easy matter as its intended circuit in -- out regards it firmware.. disconnection rail from Chip we can fed it alternative.

[waybel]

ok

Where would be a good spot to disconnect pin 4 on the pictures i sent and then where do i get 3.5 volt feed?

[Diah]

PIN 4 follow the rail it will goes to the top of the boards and there will be R this R lift one side of it.. 3.3V you have on MB the first DC to DC circuit close to socket which it connect to PSU

[nomoresonys]

This one may take a while, with a week in between tests.

[waybel]

This one may take a while, with a week in between tests.

You are correct.With the risk of doing more damage than good after installing new LED lights i bought a $40 board and installed it and the tv works fine.Thanks to all

[nomoresonys]

Thanks for the update.

[Davi.p]

You mean main board?