JVC lt-47x579 backlight comes on but nothing else

[tom66]

Re: JVC lt-47x579 backlight comes on but nothing else

If you remove it, the set should power on normally with a good picture.

I couldn't find the exact part in quantities any less than 3,000. You might have to see if the TV does get upset without it. Maybe different voltages are or eBay could be a source.

[JC1979]

Re: JVC lt-47x579 backlight comes on but nothing else

Ok, thanks. I will remove it and see how it goes.

[JC1979]

Re: JVC lt-47x579 backlight comes on but nothing else

Ok, so i took the board into an electronics shop that i have dealt with before, i had them remove ic2502. came home put the board back in, plugged everything in. hit power and nothing. I have the blue standby light on, but if i hit power on the tv or remote it does nothing. Any suggestions?

[RON_CET]

Re: JVC lt-47x579 backlight comes on but nothing else

So your saying now you don't even get the backlight glow you had before?If so and your sure you have all connectors properly seated,then possible the design of the micro on that board if it don't see any type of voltage reset will not allow unit to boot up,which means your going to have to install that IC you removed with the part number from post#15

[JC1979]

Re: JVC lt-47x579 backlight comes on but nothing else

Ok, ive looked and cant find it in quantities less than 3000. anyone out there know where i may be able to get one of these. Im willing to even change the whole board if need be at tnis point, but i cant seem to find one of those in stck anywhere either. Anyone out there have any sources tnat may be able to find either the part or the whole board.

[tom66]

Re: JVC lt-47x579 backlight comes on but nothing else

I've done some cross-referencing and found this part to be an equivalent substitute:



Farnell have it at £0.33 in single quantities, and in the 2.7V range, which is *probably* close enough.

http://uk.farnell.com/jsp/search/bro...D2031%2B203653

I just noticed it's out of stock but if you give them a ring they will get you a lead time and might even have a few left in stock.

[ben7]

Re: JVC lt-47x579 backlight comes on but nothing else

I've done some cross-referencing and found this part to be an equivalent substitute:



Farnell have it at £0.33 in single quantities, and in the 2.7V range, which is *probably* close enough.

http://uk.farnell.com/jsp/search/bro...D2031%2B203653

I just noticed it's out of stock but if you give them a ring they will get you a lead time and might even have a few left in stock.

Do you think that he could go with a 3v one? Mouser has a 2.7v one but its on-order, they do have a 3v one in stock though.

Edit: nevermind, thats still too close to 3.1v. Mouser does have a 2.5v one though!

[tom66]

Re: JVC lt-47x579 backlight comes on but nothing else

Do you think that he could go with a 3v one? Mouser has a 2.7v one but its on-order, they do have a 3v one in stock though.

I think the 3V one is what caused the problem in the first place but it may work...

[ben7]

Re: JVC lt-47x579 backlight comes on but nothing else

I think the 3V one is what caused the problem in the first place but it may work...

Mouser has a 2.5v one.

[ITH]

Re: JVC lt-47x579 backlight comes on but nothing else

hello, does it works?
i have the same issue and wanted to now if replacing IC 2502 is the solution
thanks in advance

[JC1979]

Re: JVC lt-47x579 backlight comes on but nothing else

I will be honest. I never did order the part. The tv was in the spare room. Out of sigt out of mind. Well thanks to this reminder i just ordered the part and paid feo the expidited shipping so it should be here in a day or two. After i get it back together i will definitely post and let you know if it works.

[JC1979]

Re: JVC lt-47x579 backlight comes on but nothing else

Ok. So the part came in today. Took it to guybi was going to get to solder it and first question he had was which way does it go? I showed him the picture posted by RON_CET here https://www.badcaps.net/forum/showpo...8&postcount=17 and it still leaves me two ways of putting it on. In the picture it shows one of the little prongs blacked out. any help would be apreciated. Thanks.

[tom66]

Re: JVC lt-47x579 backlight comes on but nothing else

There will be one slightly thicker lead on that device that lines up with the black pin.

[JC1979]

Re: JVC lt-47x579 backlight comes on but nothing else

Perfect. Thanks tom. Will get her all put back tomorrow and will let you know how it goes.

[Ionized]

Re: JVC lt-47x579 backlight comes on but nothing else

Perfect. Thanks tom. Will get her all put back tomorrow and will let you know how it goes.

Has this ever been resolved? I have the same model doing the same thing. The VReg readings I get are 2.48 VDC & 3.25 VDC (legs 1 & 3). Is there a test for IC 2502?

[JC1979]

Re: JVC lt-47x579 backlight comes on but nothing else

No. Never got it working. Had it soldered on. Didnt work so the set is now sitting behind a dresser In my spare bedroom. If you ever figure it out let me know.