LG 55LB5900-UV Smeary Image

[pauldow]

Hello,
I've got the subject TV. When I got it, it only had the Power indicator light, but no activity when pushing the joystick style button.
I replaced the main board, and it powers up, and looks to properly function, but the image isn't clear. It kinda looks like an old IBM CGA quality screen.

Before putting more time and money into this, does anyone know if the initial indication for this problem points to a bad T-Con board, or something within the electronics of the panel? (or something else)

Thanks,
Paul

[Diah]

Re: LG 55LB5900-UV Smeary Image

Hello,
I've got the subject TV. When I got it, it only had the Power indicator light, but no activity when pushing the joystick style button.
I replaced the main board, and it powers up,
Thanks,
Paul

after replacing MB need to inter "IN_START" service menu so you can discover if this replacement boards same label or screen size.. thought 49 55 65 all use same MB. but the setting at service menu different. you have different vlaue then with E_Z Adjust can change any things..

BTW: "IN_STOP" will reset the MB to factory condition and will register yours T-CON wifi to the new MB.

how to use IN_START IN_STOP. i posted over here many time android remote apk to use with any mobile build in IR sender.

[pauldow]

Re: LG 55LB5900-UV Smeary Image

First let me give you a very belated Thank You for pointing me in the right direction.
Too many projects put this TV on the back burner. (Actually way back.)
I also had difficulty getting the software together on my old Galaxy S4 phone. Looking through other instructions, I saw that I could use a Logitech Harmony remote. I had one that was already set for a LG television, so I'm able to get into the EZ-Adjust, In-Start and In-Stop menus and change things.

I have the panel set to 55", set the serial number (if that makes any difference), I also updated the firmware, and did the In-Stop.

There's no change to the image though.

I was looking at the EZ-Adjust panel settings. Right now it's set to:
Tool Option 1 4202
Inch 55
Tool LB59
Maker AUO
LVDS_BTS 8BIT

My service code ends in BUSCLJR
I see the B is the suppler of electronics for the TV
US is the country of manufacture
CLJR is the the type of matrix screen manufacturer, as well as information from other manufacturers of components for the TV.
That seems to be the information the main board needs to be set to. (Correct?)
However, I don't know how to translate that into settings on that Tool Option 1 page.

Thanks

Edit:
Actually scrolling through all the options, it seems changing the LVDS_BTS to 10 Bit only makes the image worse (That's the only other choice.)
I went through the Maker choices Sharp, IPS, CPT, BOE, CSOT, LGD, INX. IPS and CPT shifted the image some, but that was all.
Scrolling through Tool, the choices are LB56, LB55, LB60, LB62, LB565, LB53. There's no change to the display on any of them.
I'm not sure if any settings change in real time besides the Maker and Bits options though.

So maybe that's not the right menu to be working with.

[nomoresonys]

Re: LG 55LB5900-UV Smeary Image

Try having one ribbon cable at a time from tcon to panel plugged in, turn on tv, check display then do the same to the other side(make all connect and disconnects with tv unplugged from power)

[Diah]

Re: LG 55LB5900-UV Smeary Image

post clear focused photo for yours T-CON if any build separated with out metal shield. and all label you have on the chassis.

also photo on the first screen of IN_START

[Diah]

Re: LG 55LB5900-UV Smeary Image

One things more.. if the main firmware at mainboards didn't match the early T-CON part firmware.. will cause problem too so the last firmware 03.51.01 try to update or downgrade then update...

[Davi.p]

Re: LG 55LB5900-UV Smeary Image

swap or copy the system settings eprom from original board to replacement one..

[pauldow]

Re: LG 55LB5900-UV Smeary Image

Thank you again for the help.

Here are the photos you asked for. The board on the white background is the original.

I've read some of these boards may have the old Ball Grid Array solder problem. Do you think it would be worthwhile to do the ol' toaster oven procedure on it?

[pauldow]

Re: LG 55LB5900-UV Smeary Image

Thanks for the reply.

When I removed each side of the T-Con to panel cable, the panel showed on side disconnected as solid grey. The side that was still connected still had the bad image.

[Diah]

Re: LG 55LB5900-UV Smeary Image

did you changed any value at service M.? why the photo of IN_START show the right side not straight on screen displayed ?

google after Apache HTTP server for downgrade firmware... i think you need to try downgrade first then update or force it to flash the last firmware.. so micom version will matched main firmware.

[pauldow]

Re: LG 55LB5900-UV Smeary Image

I changed the items in Tool Option 1 as I said in my message of March 14, but I put them back the way I started. I also changed the serial number, but I don't think that affects anything.
The right side of the screen is straight. I think it was just the angle I was holding my camera.
I'm having trouble finding old firmware. The LG support site only has the current version, and other pages that I've found for firmware downgrades so far are for WebOS and network connected televisions. This one has no data connectivity.

I'll keep looking.

[Diah]

Re: LG 55LB5900-UV Smeary Image

repair yours original mainboards, swap or dump and flash the SPI from replacement to original, or in opposite way from original to replacement... keep always the dump in hand

[Davi.p]

Re: LG 55LB5900-UV Smeary Image

pauldow, i see you are not reading my suggestion, as i can know downgrading firmware is not only unuseful but is an operation not supported by maker and is available maybe sometimes from the work of some tech geeks and are not validated works so at your risk. The only eprom to swap/copy is the 24c type eprom usually around 64>512kb that contains sys settings, if there is, if not sometimes settings are in a 25q type or togheter in the main flash.

[pauldow]

Re: LG 55LB5900-UV Smeary Image

OK. I misunderstood what you were recommending I do with the EEPROM.

I put the original EEPROM on my replacement board, and the TV wouldn't turn on. I took a closer look, and while the soldering looks good around the integrated circuit, unfortunately I pulled off a couple of very small SMD components nearby. I did find them, but I don't know if I'll be able to get them back in place since they are so small.

I'll be back to let you know what happens.

Thanks
Paul

[pauldow]

Re: LG 55LB5900-UV Smeary Image

I got a tiny resistor back in place, but I wasn't able to put a capacitor back. It just wouldn't stay in place, and it doesn't look good after all the time it spent with the tip of my soldering iron.
I think I'm going to have to give up on this one.
Thank you Diah and Davi.P for all your help on this. I have two other LG televisions in my repair queue, so I think the lessons you passed on to me won't go to waste.

Thank you for all your help on this.

Paul

[Davi.p]

Re: LG 55LB5900-UV Smeary Image

Do you have tried to power on the TV? Not always caps are mandatory for the tv to work, at least near fully..
can you do a local photo of the chip (IC104)? I think is a BR24G256.. is the cap C104? I think is not so important..
Do you have some old spare electronics? You can search for a 100nF cap also not smd and put it in place of C104...
have you checked the resistance of the well resoldered resistor? How many resistors resoldered?

[pauldow]

Re: LG 55LB5900-UV Smeary Image

Oh no! I thought IC403 was the EEPROM. I got rid of the set already, so I don't have the ability to get a detailed photo to check the part numbers again. I thought IC403 was a memory circuit.

On the photo I took, I thought it looked like IC403 showed 4625. That would be the audio amplifier. (Which would be a strange place to put it on the board.) Now taking a closer look, I now see that is it 4G25, which is the EEPROM.

I did try to power it on, and I only got the backlights. No image on the screen.
I also put that circuit from the replacement board into the original one. I again get no image.
There was only the one resistor and one capacitor that came off.

While it would have been a nice size to repair, it didn't have any network connectivity, and was only 1080P resolution, so with the price of TVs these days, I had to give up at some point. I see a 50" 4K TV selling for $208 at Walmart, so while the learning experience is good, I have about 15 more TVs cluttering my house and cellar that I really have to clear out.

The previous set I worked on was a Samsung that started with a bad main board. When I put it together, I heard rattling. I thought I left some screws inside. I had to take the panel apart to see that several LED lenses came off. I found most of the 112 LED lenses were about to come off. On many LEDs, the yellow pigment came off, so they were very blue. I changed out about half of the SMD LEDs. I got tired of getting zapped when I was testing the LED strips, so I shorted a line, and blew out a SMD resistor. Placed an order for a SMD resistor assortment from China. I got that installed and I glued the lenses back on. They didn't focus right so the screen was covered in bright dots. So I bought LEDs with lenses and manually wired in all 112 of them.

I spent way too much time on that one, so I needed to figure out when to give up.

Once again, thank you for all your help with this.

[Davi.p]

Re: LG 55LB5900-UV Smeary Image

Usually there's no need of schematics to discover an eprom or others, in this case you see the eprom is near the processor and has got pin 1-4 to GND (first i2c item in the chain). The other one is near an inductor so it's a smps controller.. bye..