Lg 47lg5020

[finntricky]

got this in today, turns on fine and runs for around half hour before picture just fades out, back lights stay on, i can turn it back on and the picture is there again untill it fades yet again, this can last upto 30 mins or as short as 2 mins,
im thinking T-CON but maybe main board, video on you tube, https://www.youtube.com/watch?v=Ef6ktpfQsnw any thoughts on it guys.

[Hamie]

Re: Lg 47lg5020

Probably t-con.
Bad gamma IC maybe.
Best to check voltages.

[finntricky]

Re: Lg 47lg5020

oh how i love doing AS15F chips
ill have a look tomorrow

[finntricky]

Re: Lg 47lg5020

just had a look at this and took some readings from gamma test points. while tv is running fine, and when picture had gone, some of the readings drop by 6/7 volts when no picture, but come back up after i turn tv of and back on, so defo gamma chip prob,
but the chip is not marked AS15-F/G/U just numbers 17868A 5739, so what chip is it F/G/U or does it not matter, cant seem to get any pics uploaded at the moment.

[Hamie]

Re: Lg 47lg5020

http://m.aliexpress.com/item/32364880114.html

the part you need is

I 7868 A

Also a

I 78H68 A

Should be compatible.

[Hamie]

Re: Lg 47lg5020

Possible that as19-hg is the same.
Look at the data sheet.

[finntricky]

Re: Lg 47lg5020

so are you telling me that an AS15 chip is not going to work ?

[Hamie]

Re: Lg 47lg5020

you would need to see the data sheet.

As15 i don't believe has the same pin out as as19.

As19 might work but details on the part i7868a seem limited so on this occasion id only swap it for a i7868a or i78h68a

I certainly wouldn't risk potentially damaging the t-con over a £2 part.

[finntricky]

Re: Lg 47lg5020

i see where your comin from, im asking a few tv part supplyers to see if thay can help, with a replacement in this country, and not hong kong, and i dont understand the data sheet, so it dont help me,

[finntricky]

Re: Lg 47lg5020

UPDATE, bought a donor t-con from ebay with the same gamma ic on it, got it today and in the hope that i would not damage the ic getting it of, so went for the removal, flooded every side with flux and solder and then used heat gun to remove, as i had been told that this ic could be soldered under the chip, and it was, so useing the heat gun was the only way it was coming off,
cleaned all the pins with braid and flux, removed the bad ic from my t-con in the same manor as above,
next was the tricky bit of lineing up the pins with a solder blob under the chip and heating it to sit flat while still keeping the pins on the ic lined up.took me a few go's to get in line but sorted, soldered the 48 pins in place and checked useing a USB microscope, refitted board to tv and BINGO, tv has now been running with no probs for the last 2 hours, ONLY TIME WILL TELL,

[finntricky]

Re: Lg 47lg5020

ok, guys, after my last post i turned the tv off and put it back together, and after 20 mins it lost the pic again, so back to square one, any ideas ?

[sordids999]

Re: Lg 47lg5020

Have you tested the Gamma voltages on the Tcon ?
worth a try

[retiredcaps]

Re: Lg 47lg5020

ok, guys, after my last post i turned the tv off and put it back together, and after 20 mins it lost the pic again, so back to square one, any ideas ?

Does it run indefinitely with the back cover off? Or does it shut down any faster than 20 minutes if you heat up the t-con area with a hair dryer?

[finntricky]

Re: Lg 47lg5020

hi guys, got a bit of spare time now so having another look at this tv,
i have found a voltage reg on the T-CON that gives out 3 volts while the picture is displayed, but give no volts when picture has gone, numbers on the reg are 63A3 767DZ,
googled it and cant find any thing with that, so im 5 volts on the back tab and 3 volts on the left leg, no voltage on the right leg, middle leg is cut/not connected, any one know what may be a compatable part, or can i use any 5 volt reg ?

[finntricky]

Re: Lg 47lg5020

after stripping loads of regs of other boards and trying them on the T=CON in the hope that one would work and mostly got burnouts or not enough voltage i give up with the repair, and have now ordered another T-CON, the only worrying thing is, its come from a 46lg5010, and not 5020, all the numbers match, so just praying its the right board,

[finntricky]

Re: Lg 47lg5020

replaced T=CON and bingo, tv been running for 2 days now with no problems, job done,

[shoeless]

Re: Lg 47lg5020

hi guys, got a bit of spare time now so having another look at this tv,
i have found a voltage reg on the T-CON that gives out 3 volts while the picture is displayed, but give no volts when picture has gone, numbers on the reg are 63A3 767DZ,
googled it and cant find any thing with that, so im 5 volts on the back tab and 3 volts on the left leg, no voltage on the right leg, middle leg is cut/not connected, any one know what may be a compatable part, or can i use any 5 volt reg ?

I came across this thread because my TV (Westinghouse LCD, model TX-47F430S from '08 or so) is having the exact same problem. I haven't opened it up yet, but from some Googling, it appears to use the same TCON board as the LG you were fixing.

Anyway, for anyone else that is trying to find the 63A3 part, it is not a voltage regulator, although it does look like one. It's actually a MOSFET, part number CHM63A3PAPT made by CHENMKO. The data sheet can be found here, among other places. Hopefully this will help someone else having the same issue.

I still have not found a data sheet for the I7868A buffer chip, but they do seem to be available via a slow boat from China. I have also not seen anything conclusive as to whether or not a AS-15 is an equivalent part.

[Mstreman]

Re: Lg 47lg5020

Too new here to start a thread so I am hijacking this one. Got a refurbed TX-47F430S Westinghouse 47 inch home from the store where it was working fine, plugged it in and I have sparking voltage on every HDMI and Coax connector yet tv comes on, big W logo. Anynone heard of this before and where would I start looking for the short. It fried my cable box and i am about to go check exact voltage from the short.

[Mstreman]

Re: Lg 47lg5020

Solved. Somewhere the ground has been used as a neutral such that when a 3 prong plug is plugged into he outlet, regular ac current is thrown onto the ground everywhere. When the co0-0ax is attached to the cable box the current runs out to the co-ax ground point. Anytime sparks fly from the co-ax or HDMI port look to a hot neutral/ground in the outlet. The problem can go unnoticed for decades so long as inly 2 pronged plugs are used--introduce a 3 prong with hot ground and sparks will fly

[Davi.p]

Re: Lg 47lg5020

"Too new here to start a thread"
is not good, wasted minutes reading..!!