LG TV turn off/on also ticking noise

[TheDragon]

Hi all, I searched through the forums before posting.
My LG LW650T suddenly stopped working a few days ago, and although I've started the search to replace it as it was old, the picture quality was good and would love to repair if possible to use elsewhere and save some electrical waste.
I gave it to a local repair place who said he would do some basic checks, and reflow it, but it never worked so didn't charge me.

The fault is:
Press the power on via remote.
I hear the relay and power LED turns on.
The other control LED's cycle on/off as per usual.
Then the power LED goes off but relay does not click.
Pressing the power button on remote again, I hear the relay click (I assume its goes off).
I'm not sure if this is some sort of protection circuit or other.

Anyway, I decided to look myself. I turned on via remote and as before the power LED goes off.
I can hear a very faint ticking noise and using a audio field recorder to monitor the sound, I've sort of narrowed it down to the area highlighted in the red box (Image attached).

When I took the image, as I was editing it I also noticed something odd.
The box I highlighted in green, seems like a component missing?

Can anyone guide me or have experience with these TV's.
Thank you

[Diah]

Re: LG TV turn off/on also ticking noise

upload complete photo of yours mainboards

BTW : did you see if there are sign on the mainboards after you turn it on... if there optical audio output -- its led lid on... or if you insert USB drive if the led of the usb drive blinked ??

[nomoresonys]

Re: LG TV turn off/on also ticking noise

Well you're at least missing the heatsink that covers those chips, did you get it back? there's good pictures of the boards there if you click the image, the heatsink covers that area you refer to tho: https://spares2repair.co.uk/sound-vi...av/lg/42lw650t

[Diah]

Re: LG TV turn off/on also ticking noise

Well you're at least missing the heatsink that covers those chips, did you get it back? there's good pictures of the boards there if you click the image, the heatsink covers that area you refer to tho: https://spares2repair.co.uk/sound-vi...av/lg/42lw650t

heatsink yea but i dont think there parts missing..

[nomoresonys]

Re: LG TV turn off/on also ticking noise

Probably not, seems that if you look real close you would see signs of solder if there was anything ever there.

[R_J]

Re: LG TV turn off/on also ticking noise

The missing part at M20 is the same part M22, M23, (metal loop), they are used to keep the heatsink away from the board, I suspect someone removed it when they tried to re-heat the ic's, there does look like some flux residue around ic101

[TheDragon]

Re: LG TV turn off/on also ticking noise

upload complete photo of yours mainboards

BTW : did you see if there are sign on the mainboards after you turn it on... if there optical audio output -- its led lid on... or if you insert USB drive if the led of the usb drive blinked ??

Good suggestions. There is no light from the Toslink port and plugging in a USB flash drive, it's indicator light does not flash. I also tried the USB drive whilst plugged in before turning on. Nothing.

I have uploaded images of the two main boards.

Well you're at least missing the heatsink that covers those chips, did you get it back? there's good pictures of the boards there if you click the image, the heatsink covers that area you refer to tho: https://spares2repair.co.uk/sound-vi...av/lg/42lw650t

I had taken off the heatsink myself, to check where the sound was coming from and see if the CPU gets warm, very slight only.

The missing part at M20 is the same part M22, M23, (metal loop), they are used to keep the heatsink away from the board, I suspect someone removed it when they tried to re-heat the ic's, there does look like some flux residue around ic101

Indeed you are right, just some sponge type pads that sit underneath heatsink as per other part designations.

[Diah]

Re: LG TV turn off/on also ticking noise

now we need some measurements on the sockets at powerboards which it goes to mainboards.. turn on the set ( did it response to RC to power on?? ) while the set on and during the time front led indicator blinking measure the 12 & 24V on the sockets if it exist and remain. if you have missing one of above Voltage. then you need to disconnect the mainboards totally from powerboards, locate on the sockets this pins to make jumpers ( to run powerboards as stand alone )
3.5V and PWR-ON
3.5V and DRV-ON
with this 2 jumpers in place you should have 12 & 24V on the same sockets.

[TheDragon]

Re: LG TV turn off/on also ticking noise

Plugging in, all 3.5v rails are fine

Turning on via RC:

12v rails read 11.8v
24v rails read 24.1v
3.5v rails read 3.5v as before.

So far so good? (12v rails being 11.8v)

[Diah]

Re: LG TV turn off/on also ticking noise

Plugging in, all 3.5v rails are fine

Turning on via RC:

12v rails read 11.8v
24v rails read 24.1v
3.5v rails read 3.5v as before.

So far so good? (12v rails being 11.8v)

sound good, mainboards had sign of life. as it response on RC to power on i think you can put it in standby mode too.. but we need now when it on and you have all voltage as you measured above.. send IN_STOP command followed with 4 digital code codes could be: 0 4 1 3 / 8 7 4 1 / 8 7 4 3 / 7 7 7 7 / 0 0 0 0 / 8 8 7 8
search after IN_STOP you can Diy it too if you dont have mobile with IR blaster to use LG service remote apk. if the set receive the command and accept the 4 digital code it will turn off to standby. this will make hard reset to all the mainboards.

[TheDragon]

Re: LG TV turn off/on also ticking noise

sound good, mainboards had sign of life. as it response on RC to power on i think you can put it in standby mode too.. but we need now when it on and you have all voltage as you measured above.. send IN_STOP command followed with 4 digital code codes could be: 0 4 1 3 / 8 7 4 1 / 8 7 4 3 / 7 7 7 7 / 0 0 0 0 / 8 8 7 8
search after IN_STOP you can Diy it too if you dont have mobile with IR blaster to use LG service remote apk. if the set receive the command and accept the 4 digital code it will turn off to standby. this will make hard reset to all the mainboards.

OK thanks for the help.

So I made the IR+audio jack hack with some old diodes as you suggested.
To test the IR hack I played wav files through my laptop and used my phone camera to see if they were getting signals.

Unfortunately the In STOP & POWER ONLY commands did not show on diodes.
The EZ START & IN START commands did show my IR.

I have another smaller LG TV, so tried the hack on it. The EZ-adjust commands worked and code 0413 also worked for it.

So what shall I do next?
I have a Oneforall remote control URC-7544 that I once used to get into service menu of the LW650T, can I use this like a service remote?

[Diah]

Re: LG TV turn off/on also ticking noise

OK thanks for the help.

So I made the IR+audio jack hack with some old diodes as you suggested.
To test the IR hack I played wav files through my laptop and used my phone camera to see if they were getting signals.

Unfortunately the In STOP & POWER ONLY commands did not show on diodes.
The EZ START & IN START commands did show my IR.

your Diy seem fine. but the problem with playing the wave file try other player and be sure the channel of audio it had output.. other file working it may belong to stereo channel if they play left or on right.. same you need the volume to full of headphone and the main volume.

[TheDragon]

Re: LG TV turn off/on also ticking noise

your Diy seem fine. but the problem with playing the wave file try other player and be sure the channel of audio it had output.. other file working it may belong to stereo channel if they play left or on right.. same you need the volume to full of headphone and the main volume.

Yes you're right, STOP and POWER ONLY are mono files, other two are stereo.

I created the IR hack from this guide
https://www.instructables.com/DIY-In...r-iPhone-iPod/

does that mean I don't need two LEDS but only 1 for the mono wav files?

Because in that guide I followed, the GND connection is not used

[Diah]

Re: LG TV turn off/on also ticking noise

Yes you're right, STOP and POWER ONLY are mono files, other two are stereo.

I created the IR hack from this guide
https://www.instructables.com/DIY-In...r-iPhone-iPod/

does that mean I don't need two LEDS but only 1 for the mono wav files?

Because in that guide I followed, the GND connection is not used

watch this video

[TheDragon]

Re: LG TV turn off/on also ticking noise

Thanks. I watched that video you linked.
What I figured out was the STOP command would only work on left channel, so it was a matter of testing and it worked on my other LG tv.

So I tried it on my broken one. I tried all the codes.
I took my time and went through the process twice.
After each set of numbers I waited a few minutes before doing again
Unfortunately it didn't work.

I'm not sure if it read the IN STOP command.

Back to square one?

[Diah]

Re: LG TV turn off/on also ticking noise

I'm not sure if it read the IN STOP command.
Back to square one?

if you connect the TV with LAN Ethernet. can you see the green led on the socket turn on? also you need to log in at yours routers, find out if the there IP asigned for it in case yes so you can use apache LG server on PC

[TheDragon]

Re: LG TV turn off/on also ticking noise

if you connect the TV with LAN Ethernet. can you see the green led on the socket turn on? also you need to log in at yours routers, find out if the there IP asigned for it in case yes so you can use apache LG server on PC

I tried the network connection, no light on my network switch or new assigned addresses listed. Tried a few cables.
I'm gonna try the LED method a few more times.

I've also got a usb to RS232 converter adapter but won't work in windows 10. I thought maybe send commands to the TV via RS232 but because there is no power to the USB socket, Toslink and ethernet, I think the RS232 won'tl work either. It seems only IR communication is working.

My phone is also LG which has a built in IR, but because I've rooted it and custom rom the IR is not supported. I also have a samsung tablet which is suppose have a IR too, but ive put a custom rom on that too and the IR is not supported. I will see if I can take one of them back to original rom.
That app you suggested, do I need to buy it?

I did try an app called Universal TV Remote-ZaZa Remote. With that I can control my other LG tv using the 3.5mm IR adapter, but it has no options for service menu or STOP START commands.

Thanks for your patience

[TheDragon]

Re: LG TV turn off/on also ticking noise

OK, So tried an app called IRPLUS WAVE. Really clever app that allows me to use the IR Audio MOD. I then found a LG external device control PDF whcih had IR codes for some modern TV's.
I then converted the In-Stop code with a program called IrScrutinizer, so I can use with IRPLUS.

Using the IR MOD and IRPLUS, I transmitted the In-Stop code to my other LG TV and it works, goes to reset (didn't ask for code)

I then tried it on my broken TV. I tried all the codes. It still did not work

[Diah]

Re: LG TV turn off/on also ticking noise

OK, So tried an app called IRPLUS WAVE. Really clever app that allows me to use the IR Audio MOD. I then found a LG external device control PDF whcih had IR codes for some modern TV's.
I then converted the In-Stop code with a program called IrScrutinizer, so I can use with IRPLUS.

Using the IR MOD and IRPLUS, I transmitted the In-Stop code to my other LG TV and it works, goes to reset (didn't ask for code)

I then tried it on my broken TV. I tried all the codes. It still did not work

good mode you did indeed..

yours mainboards sound no communication between NAND and main IC.
you need to buy mainboards at any way. or you can throw yours MB complete in oven ( not with air ) for round 10 minutes who knows it could give others sign what you are missing now

BTW: can you upload yours .wav files you did ??

[TheDragon]

Re: LG TV turn off/on also ticking noise

good mode you did indeed..

yours mainboards sound no communication between NAND and main IC.
you need to buy mainboards at any way. or you can throw yours MB complete in oven ( not with air ) for round 10 minutes who knows it could give others sign what you are missing now

BTW: can you upload yours .wav files you did ??

Yeah, Looks looks something complex or just crazy.
After more research, I test PSU board like you said before using jumpers to turn on and I also use jumper to turn on backlights and they work.
I was also getting 56v at the LED+ so that was ok.

I then tested LVDS cable from mainboard to T-con, there is no 12v power going to the t-con board when the TV powers on.

I was reading how 2 transistors and a mosfet control this 12v on the mainboard to supply the T-Con board. They are Q505, Q506, Q507 (mosfet) .
So here could be the problem. There is a repair kit with these parts, but from USA and it's too expensive to ship here.

I tried to follow the 12v path but I'm not good with complex electronics,
but think it is these parts, as the 12v stops somwhere there and does not continue to connection for LVDS cable.

I then had an idea, I found on the mainboard the same mosfet, which is used by the CI card module which I have never used and there is one used by wireless feature which I don't use too. So I desoldered the CI mosfet and swapped with Q507. Tv still did not work, but I am thinking to change the transistors too, there are some duplicates.
I can test the transistors when I desolder them, but can't test the mosfets.

I will see if this works. I think my T-con board is ok, my PSU is ok too.
Just something on mainboard.

I have already followed a guide on how to reflow the board but I done the CPU not all the board. It didn't work. I'm losing my mind lol.

I have attached the two WAV filesI created that worked for me.
I have also included two Irplus files that do the same but with the IRPLUS WAVE app