Backlight issue LG 50ln5600

[7thkey]

Re: Backlight issue LG 50ln5600

You may not actually need to desolder the connector, most led strips have a + and - points, you could simply connect those points with a bit of wire to the board.

So you think bypass the connectors all together ? Jump the leads with small wires? Thing is thing is if I take a reading of the green board with no connected LED strips the connection points the 4th connection is the voltage drop.

So you don't think one of the led strips could be bad and still light up?

[Hamie]

Re: Backlight issue LG 50ln5600

They shouldn't light up if the LEDs are faulty.

if you had a boost converter you could totally rule it out. By setting the converter at around 30v and touching the + -, if only some of the strings light then you would know that somehow the LEDs are faulty.

Alternatively You could link up 3 x 9v batteries in series and touch the + - of the strings and see if they light up.

[ReeceyBurger123]

Re: Backlight issue LG 50ln5600

Thats true but the pad is normally very small.

[Electrolab1]

Re: Backlight issue LG 50ln5600

Interesting you were talking about the 78V. I have two in here, the voltage measured 78V, but no display. I was checking voltages, when suddenly it went up to 115V, and the LEDS came on! hmmm.

[7thkey]

Re: Backlight issue LG 50ln5600

I may have figured it out. While all my LEDs do light up I noticed one L1 strip was drawing more than the others. Sure enough I switched that strip with the strip on set 1. Now line 2,3,4 light up instead of 1,5,6.

I noticed the extra draw when I was discharging the board in diode mode after TV was off. All the LED s slowly faded at the same rate except that L1 strip it stayed lit longer. So it seems to be just enough to fault and trigger the protection shut off.

Anyway should get the new strip in a couple days. I'll let you all know if the replacement fixes it.

[ReeceyBurger123]

Re: Backlight issue LG 50ln5600

Ok some progress, good luck with it

[Terryfictv]

Re: Backlight issue LG 50ln5600

I would like to join the end of this thread and thank you for your progress to this point !
Similar situation here with 47LN5400...I just opened my third one in two weeks. Currently,one is running normal ( had loose mounting screws on main board ). LED voltage is 104.0v at P801 +...... Unplugged, +170v ( open = no current ). If you read 78v, it must mean shorted LED strip...more on this later.

[Shane711]

Re: Backlight issue LG 50ln5600

I need help, I have a LG 50LN5600 and I am trying to locate the EEPROM on the main board. When I got this TV it would freeze on the LOGO, tried to find an EEPROM for it but I could not so I bought a used Main board and now the TV works, but I want to attempt to fix the old board by coping the firmware from the good board to the old board but which IC is the EEPROM?

I tried search the numbers on the ICs but I have not had any luck, it is like this board does not have an EEPROM.

[ReeceyBurger123]

Re: Backlight issue LG 50ln5600

I need help, I have a LG 50LN5600 and I am trying to locate the EEPROM on the main board. When I got this TV it would freeze on the LOGO, tried to find an EEPROM for it but I could not so I bought a used Main board and now the TV works, but I want to attempt to fix the old board by coping the firmware from the good board to the old board but which IC is the EEPROM?

I tried search the numbers on the ICs but I have not had any luck, it is like this board does not have an EEPROM.

Start a separate thread mate you will have more luck doing that

[Shane711]

Re: Backlight issue LG 50ln5600

I do not know how to start a new thread, seems to be impossible.

[Agent24]

Re: Backlight issue LG 50ln5600

I tried search the numbers on the ICs but I have not had any luck, it is like this board does not have an EEPROM.

What are the numbers on the ICs? Look at the 8-pin ones, it's most likely one of those.

IC100 is my guess (The rest look like they are DC-DC converters with those inductors nearby)

I suppose if there really is no external EEPROM, they might program the code directly into the main processor IC with an internal EEPROM over JTAG or something.

[Shane711]

Re: Backlight issue LG 50ln5600

( 4HA7 03G3 04 ) are the numbers on IC100

[7thkey]

Re: Backlight issue LG 50ln5600

Replacing that led string fixed it.

[7thkey]

Re: Backlight issue LG 50ln5600

Replacing that led string fixed it.

[budm]

Re: Backlight issue LG 50ln5600

Good job, these TV's with LED backlights sure are not reliable.

[Shane711]

Re: Backlight issue LG 50ln5600

Well I have an EEPROM reader and I have successfully read an EEPROM from another TV then I tried every chip on the LG 50ln5600 and I had no luck so I am going to assume it does not have an EEPROM. If anyone knows where I can find information on this I would like a link so I can learn how to reprogram these non-EEPROM boards. Untill then I have to file this problem for another day. Thank you so much everyone.

[Steve L]

Re: Backlight issue LG 50ln5600

( 4HA7 03G3 04 ) are the numbers on IC100

Shane:
I believe the eeprom is IC2405, very near the power connector. I don't monkey with ICs on these surface mount bds. normally. But from my past experience going back to '80s and '90s., serial eeproms that are cmos design will start with a 4 with 3 more digits for serial eeproms. I have a 50LN5700 here and IC2405 looks like it's printed 4327,(used to mean 27kbytes/cmos.) Before 3.3v system op. voltage times, they were 5v ttl serial eeproms starting with 74xx. xx for kbits/bytes, can't recall bits or bytes. There were also ram and buffer ICs and etc. that were cmos and would be 74cxxx, instead of ttl is 74lsxxx eg.

You should be able to try a software upgrade/reload. Get software from LG dot com along with instructions, and put usb stick into TV and plug TV in.

Regards if you're still looking,
Steve L.

[Agent24]

Re: Backlight issue LG 50ln5600

I don't think 27k ROMs exist - at least not anymore if they ever did - everything is usually a power of 2 because of binary.

Edit: found some list of old ones here: http://www.intel-vintage.info/intelmemory.htm there's a 4308 8k and a 4316 16k, nothing 27k though. I'd be very surprised if they still used that numbering scheme today.

A lot of SMD chips these days have manufacturer-specific codes instead of the actual model number printed on them. 4HA7 03G3 like on IC100 here is probably in that format but unfortunately nothing shows up in Google!

In fact, even as little as 2 digits, like the 4H might be the model number, the rest could all be date\batch codes.

[Steve L]

Re: Backlight issue LG 50ln5600

Agent24: Shane711:
Yes. 27k is no good. Although I had a hard time reading that small print. Yes, I kind of posted hastily-should have tried a little research 1st. It's been a long long time since I delt with CPU bd. schematics-in fact on TVs, since microcontroller ICs, but mostly non-TV specifically designed CPU digital electronics applications.

So I checked some bds.
I have a samsung that has a chip near what seems to be the TV micro. It's printed 24H01RP-(sp).
On a samsung main schem, I find the TV micro eeprom as device type 24c256.That's the # profile I was trying to think of. Those were used as thru-hole ICs in early 2000's, and '90s and before, also. (Usually 24c08/16/32)
Ya. 4xxx was '80s CMOS logic chip. Glad you caught. I'm old now.

On my 50LN5700, There are no chips on bottom of board. And 8 pin chip near kybd conn and what appears TV micro, is IC100 with "4HA7 D2MS" print on chip. Prob like you said. D2MS date code? no schem. for LG.

I wonder if he tried reloading software from LG.com?

I also just fixed a 42LD520 that was locked-up with white screen and the words "POWER ONLY, V.xx.xx.xx." I downloaded software update and fixed.

[Agent24]

Re: Backlight issue LG 50ln5600

Same 4HA7 IC100 chip turns up http://www.qariya.info/vb/showthread...=144590&page=3 in 32ln5100 too.

One of the guys posted ROM dumps, in the 39LN5100.rar is a file which says 4HA7=24C256

Google search https://www.google.com/search?q=4HA7...&q=24C256+4HA7 turns up a few LG parts with reference to 4HA7 being a 24C256.

Added the files I found for the 39LN5100 and 32LN5110 though just in case someone wants them.

Can't find any dumps for a 50LN5600 so far though