LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

[Ashhad101]

Hey guys i have a 47inch lg smart tv which i bought in 2012 its been running fine but now its gone into a problem basically when i turn on the tv no picture comes (back light works) but i can hear sound coming from channels it also shows horizontal flickering lines, so i opened the tv and searched for bad capacitors but there are no bad capacitors. Power supply is fine so i guess the problem lies in t-con board,main board and tv panel.So panel itself has never been damaged or came contact with water so i think its fine but i guess t-con board has problem but iam not sure about it, i also gave my tv to some repairmen but in my country they all work on trail and error bases, so they just told me that tv panel has fault but i highly doubt it. Iam posting pictures of my problem then you will have a better idea, by the way i removed one of two lcd wires from t-con and then tv shows half side full white i dont know what that means.Please help me guys as this is the only tv i have and i cant afford a new one. Thanks

[tvtimmy]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

Most likely the mainboard. Remove the heatsink and use a heat gun on low for about 45 sec. on the chip. Should turn on, opinions differ as to how long it will last. Ive done 30 or so and nobody has called about one. Fist one was early last year.

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

Yeah i used a hair dryer to heat the chip for about 6-7 mins but that didn't work either. should i try it again?

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

Most likely the mainboard. Remove the heatsink and use a heat gun on low for about 45 sec. on the chip. Should turn on, opinions differ as to how long it will last. Ive done 30 or so and nobody has called about one. Fist one was early last year.

Yeah i used a hair dryer to heat the chip for about 6-7 mins but that didn't work either. should i try it again?

[diif]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

Yeah i used a hair dryer to heat the chip for about 6-7 mins but that didn't work either. should i try it again?

Not with a hair dryer. It's not hot enough, you're looking to melt the solder balls under the chip.

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

Not with a hair dryer. It's not hot enough, you're looking to melt the solder balls under the chip.

ohh!! i thought a hair-dryer would work nevertheless i will borrow a heat gun from my friend and will use it. I will tell you my results in day or two meanwhile are there any other things which i should know? Thanks

[diif]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

Add some flux before you add heat and watch a couple of videos on reflowing on youtube to give you an idea of the process and temperatures involved.
Using a heatgun can be risky due to the temperatures involved and a lack of control.

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

Add some flux before you add heat and watch a couple of videos on reflowing on youtube to give you an idea of the process and temperatures involved.
Using a heatgun can be risky due to the temperatures involved and a lack of control.

Thanks for great information i will practice it before i use it on my tv. Thanks again i will soon update you with my results.

[diif]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

Thanks for great information i will practice it before i use it on my tv. Thanks again i will soon update you with my results.

You're welcome. Yes do practice. It took a few scrap boards before the correct temperatures and profile was dialed on my on rework machine and I use three temperature probes to monitor the process. tytimmy as you can see has done quite a few so has a feel for the process. A cheap digital probe will cost you about $5 and may be worth purchasing to help in your repair.
Ideally the whole board needs to be heated up before reflowing the chip to reduce the chance of thermal shock. It's not a good idea to have centre of the board at least 230c and the edges of the board at room temperature.

Here's a video of an xbox reflow to give you an idea. https://www.youtube.com/watch?v=MEvfBS6Tams

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

You're welcome. Yes do practice. It took a few scrap boards before the correct temperatures and profile was dialed on my on rework machine and I use three temperature probes to monitor the process. tytimmy as you can see has done quite a few so has a feel for the process. A cheap digital probe will cost you about $5 and may be worth purchasing to help in your repair.
Ideally the whole board needs to be heated up before reflowing the chip to reduce the chance of thermal shock. It's not a good idea to have centre of the board at least 230c and the edges of the board at room temperature.

Here's a video of an xbox reflow to give you an idea. https://www.youtube.com/watch?v=MEvfBS6Tams

ohh thanks for the info i was going to heat the chip only, guess i will first use a hairdryer to heat up whole motherboard and then i will heat the chip with a heat gun and luckily i have temperature measuring device in my house will use it to monitor temperature on chip, by the way how much temperature chip needs to reflow 230C? or higher? and thanks for
the video i will watch it again.

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

hey guys i was wondering my tv does not show any picture but sound comes perfectly from all sources (e.g hdmi,usb,digital opt,cable etc) so is it possible that the problem is in main board? or its fine? can anybody put light on this it would be really helpful.Thanks

[vinceroger69]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

This is the method i have used on various reflows and have had good success i have kept all the items i have re flowed and all are still working fine mainly a laptop two xbox 360 and a lg tv every body has difefrent methods this one i was advised by momaka a member on this forum

First and foremost, you *will* need proper flux for lead-free solder. Regular rosin may not do so well (in fact, it may burn of and harden way before the lead-free solder melts, which may actually cause an even worse chance of successful reflow). Kingo RMA-218 is a cheap Chinese generic that works fairly well. But I think Kester had some better fluxes available.

As for the reflow process itself:

1) Clean around the chip you will be reflowing with 90+% IPA (isopropyl alcohol).

2) Make a heat shield for any nearby capacitors. I've seen way too many people not do that and pop the caps on their board. Aluminum foil works fine for that. Don't completely cover the caps, though - we are not trying to cook a Turkey here . Just cover them on the side that they are likely to get hit by hot air from the heat gun.

3) Place the board on some kind of a metal stand so that you have access to both the top side and the bottom. I usually do this by clamping metal rods to a table and have the metal rods sticking past the edge of the table. Then I place the board there, so I can have access to both the top and the bottom of the board. This way, I don't have to flip the board when it is hot, which greatly reduces stress on the various BGA components on the board. The chip you are trying to reflow/remove/rebal should always be on the top side.

3a) (Optional, but very highly recommended) If you have a type-K temperature thermometer, put the thermocouple probe near the chip you will be reflowing. Don't put it on the ship itself or under its BGA, as that may actually cause the chip to move out of place once it is hot. As for type-K thermometers, the Lutron TM-902C can be found for about $5 on eBay, and I highly recommend it.

4) Assuming you have a high-power dual temperature heat gun, turn ON the heat gun to the low setting (which should be around 500 Watts, give or take 150) and heat the board from the bottom side, focusing mostly in the area under the BGA chip you are trying to reflow.

5) When the temperature readout of the type-K thermometer reaches 150C-160C (if you don't have a thermometer, it will probably take 3-5 minutes to get up to that temperature), stop heating and gently apply flux around the edges of the chip. The hot air coming from between the board and the chip will actually suck the flux right into the BGA, so no need to worry how to put the flux under the chip. Also, do NOT drown the chip in flux. Too much flux can actually cause the solder balls to move around and short out to each other.

6) Switch the heat gun to the high setting (should be around 1000 Watts) and continue heating the chip from the bottom of the board.

7) When the temperature reaches around 180C (again, if you don't have a thermometer, this could take another 2-3 minutes), stop the heatgun and carefully move it to the top side of the board. Begin heating the top side of the board on the high setting again.

8) When the temperature reaches around 220-230C and stays in that range for 10 seconds (again, if you don't have a thermometer, this could take another 2-3 minutes), turn OFF the heat gun.

9) Let the board cool down for about 10-20 minutes (this will depend on how hot/cold it is where you are working).

10) Remove protective heat shield around caps and test the board. (Don't forget to add thermal compound to the CPU and GPU, of course. )

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

This is the method i have used on various reflows and have had good success i have kept all the items i have re flowed and all are still working fine mainly a laptop two xbox 360 and a lg tv every body has difefrent methods this one i was advised by momaka a member on this forum

First and foremost, you *will* need proper flux for lead-free solder. Regular rosin may not do so well (in fact, it may burn of and harden way before the lead-free solder melts, which may actually cause an even worse chance of successful reflow). Kingo RMA-218 is a cheap Chinese generic that works fairly well. But I think Kester had some better fluxes available.

As for the reflow process itself:

1) Clean around the chip you will be reflowing with 90+% IPA (isopropyl alcohol).

2) Make a heat shield for any nearby capacitors. I've seen way too many people not do that and pop the caps on their board. Aluminum foil works fine for that. Don't completely cover the caps, though - we are not trying to cook a Turkey here . Just cover them on the side that they are likely to get hit by hot air from the heat gun.

3) Place the board on some kind of a metal stand so that you have access to both the top side and the bottom. I usually do this by clamping metal rods to a table and have the metal rods sticking past the edge of the table. Then I place the board there, so I can have access to both the top and the bottom of the board. This way, I don't have to flip the board when it is hot, which greatly reduces stress on the various BGA components on the board. The chip you are trying to reflow/remove/rebal should always be on the top side.

3a) (Optional, but very highly recommended) If you have a type-K temperature thermometer, put the thermocouple probe near the chip you will be reflowing. Don't put it on the ship itself or under its BGA, as that may actually cause the chip to move out of place once it is hot. As for type-K thermometers, the Lutron TM-902C can be found for about $5 on eBay, and I highly recommend it.

4) Assuming you have a high-power dual temperature heat gun, turn ON the heat gun to the low setting (which should be around 500 Watts, give or take 150) and heat the board from the bottom side, focusing mostly in the area under the BGA chip you are trying to reflow.

5) When the temperature readout of the type-K thermometer reaches 150C-160C (if you don't have a thermometer, it will probably take 3-5 minutes to get up to that temperature), stop heating and gently apply flux around the edges of the chip. The hot air coming from between the board and the chip will actually suck the flux right into the BGA, so no need to worry how to put the flux under the chip. Also, do NOT drown the chip in flux. Too much flux can actually cause the solder balls to move around and short out to each other.

6) Switch the heat gun to the high setting (should be around 1000 Watts) and continue heating the chip from the bottom of the board.

7) When the temperature reaches around 180C (again, if you don't have a thermometer, this could take another 2-3 minutes), stop the heatgun and carefully move it to the top side of the board. Begin heating the top side of the board on the high setting again.

8) When the temperature reaches around 220-230C and stays in that range for 10 seconds (again, if you don't have a thermometer, this could take another 2-3 minutes), turn OFF the heat gun.

9) Let the board cool down for about 10-20 minutes (this will depend on how hot/cold it is where you are working).

10) Remove protective heat shield around caps and test the board. (Don't forget to add thermal compound to the CPU and GPU, of course. )

thanks for the hard work i highly appreciate it,will try it soon. THANKS

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

guys i have question which is bothering me alot as you know i have 47inch lg smart tv which is not working properly sound comes perfectly through all sources but no picture comes sometimes screen shows lines and sometimes it goes white but no words or any picture is visible so some members on this forum told me to do re-flow soldering but i was thinking that how could mother board be faulty as sound comes perfectly from it and i can change channels but iam no genius its just a guess can anybody please tell me that should i first re-flow solder or should i buy a new T-con board?? Please Help

[oldschoolgamer]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

guys i have question which is bothering me alot as you know i have 47inch lg smart tv which is not working properly sound comes perfectly through all sources but no picture comes sometimes screen shows lines and sometimes it goes white but no words or any picture is visible so some members on this forum told me to do re-flow soldering but i was thinking that how could mother board be faulty as sound comes perfectly from it and i can change channels but iam no genius its just a guess can anybody please tell me that should i first re-flow solder or should i buy a new T-con board?? Please Help

You can't really make it worse to be honest. You can't break what's already broken so you should try heating it and if that fails just order the new board. I've had lots of experience with heating stuff like GPU's etc. and just like a previous post says, you don't know how long it will last. Could be a few days or months or years depending on how well the reflow goes.

Basically try it first and at least if it works it saves you money for now. If it doesn't work or you make the board worse it was already broken to begin with.

Also you won't make it worse unless you focus on the one area for ages without moving the heat gun around or set it way too high and do it for too long. Just do low for 45 seconds or so like @tvtimmy said and it should be fine.

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

You can't really make it worse to be honest. You can't break what's already broken so you should try heating it and if that fails just order the new board. I've had lots of experience with heating stuff like GPU's etc. and just like a previous post says, you don't know how long it will last. Could be a few days or months or years depending on how well the reflow goes.

Basically try it first and at least if it works it saves you money for now. If it doesn't work or you make the board worse it was already broken to begin with.

Also you won't make it worse unless you focus on the one area for ages without moving the heat gun around or set it way too high and do it for too long. Just do low for 45 seconds or so like @tvtimmy said and it should be fine.

yeah i understand it pretty well but what if my mother board is not broken as i mentioned above that sound comes i can change channels in that case i would make it even worse but iam no genuis or can i reflow a t-con board first it also has a main chip in it. what do you suggest should i just directly reflow my mother board or first i should check T-con board?

[budm]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

https://www.badcaps.net/forum/attach...1&d=1505242909

Are those dark clouds like on the screen always like that in one place and they do not move?
That cloud looks like bad screen to me. From my experience, T-CON cannot cause horizontal lines.

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

https://www.badcaps.net/forum/attach...1&d=1505242909

Are those dark clouds like on the screen always like that in one place and they do not move?
That cloud looks like bad screen to me. From my experience, T-CON cannot cause horizontal lines.

no this is backlight bleed when any picture comes they just go away this is just backlight or you can say blacks of tv but these lines do move when new input is selected sometimes whole screen goes gray.

[diif]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

This is the method i have used on various reflows and have had good success i have kept all the items i have re flowed and all are still working fine mainly a laptop two xbox 360 and a lg tv every body has difefrent methods this one i was advised by momaka a member on this forum

First and foremost, you *will* need proper flux for lead-free solder. Regular rosin may not do so well (in fact, it may burn of and harden way before the lead-free solder melts, which may actually cause an even worse chance of successful reflow). Kingo RMA-218 is a cheap Chinese generic that works fairly well. But I think Kester had some better fluxes available.

As for the reflow process itself:

1) Clean around the chip you will be reflowing with 90+% IPA (isopropyl alcohol).

2) Make a heat shield for any nearby capacitors. I've seen way too many people not do that and pop the caps on their board. Aluminum foil works fine for that. Don't completely cover the caps, though - we are not trying to cook a Turkey here . Just cover them on the side that they are likely to get hit by hot air from the heat gun.

3) Place the board on some kind of a metal stand so that you have access to both the top side and the bottom. I usually do this by clamping metal rods to a table and have the metal rods sticking past the edge of the table. Then I place the board there, so I can have access to both the top and the bottom of the board. This way, I don't have to flip the board when it is hot, which greatly reduces stress on the various BGA components on the board. The chip you are trying to reflow/remove/rebal should always be on the top side.

3a) (Optional, but very highly recommended) If you have a type-K temperature thermometer, put the thermocouple probe near the chip you will be reflowing. Don't put it on the ship itself or under its BGA, as that may actually cause the chip to move out of place once it is hot. As for type-K thermometers, the Lutron TM-902C can be found for about $5 on eBay, and I highly recommend it.

4) Assuming you have a high-power dual temperature heat gun, turn ON the heat gun to the low setting (which should be around 500 Watts, give or take 150) and heat the board from the bottom side, focusing mostly in the area under the BGA chip you are trying to reflow.

5) When the temperature readout of the type-K thermometer reaches 150C-160C (if you don't have a thermometer, it will probably take 3-5 minutes to get up to that temperature), stop heating and gently apply flux around the edges of the chip. The hot air coming from between the board and the chip will actually suck the flux right into the BGA, so no need to worry how to put the flux under the chip. Also, do NOT drown the chip in flux. Too much flux can actually cause the solder balls to move around and short out to each other.

6) Switch the heat gun to the high setting (should be around 1000 Watts) and continue heating the chip from the bottom of the board.

7) When the temperature reaches around 180C (again, if you don't have a thermometer, this could take another 2-3 minutes), stop the heatgun and carefully move it to the top side of the board. Begin heating the top side of the board on the high setting again.

8) When the temperature reaches around 220-230C and stays in that range for 10 seconds (again, if you don't have a thermometer, this could take another 2-3 minutes), turn OFF the heat gun.

9) Let the board cool down for about 10-20 minutes (this will depend on how hot/cold it is where you are working).

10) Remove protective heat shield around caps and test the board. (Don't forget to add thermal compound to the CPU and GPU, of course. )

A nice tutorial but I would add step 11) Cool with desk fan.

All rework profiles show a short cooling down period. Most of the decent videos on YouTube show rework being cooled with a fan. And the rework stations I've seen all have fans.

[Ashhad101]

Re: LG Smart Tv No picture but has flickering horizontal lines.PLEASE HELP

https://www.badcaps.net/forum/attach...1&d=1505242909

Are those dark clouds like on the screen always like that in one place and they do not move?
That cloud looks like bad screen to me. From my experience, T-CON cannot cause horizontal lines.

have a look at these pictures this happened when i was playing my blu-ray player,could this be related to TCON?