Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

[freakaftr8]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Poor connection to the laps most likely created this. It's like a bottle neck in current. The weakest point will melt.

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Nothing looks burned on the board

[freakaftr8]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

You may have to either search for the lamp holders or carefully solder a bridge with a wire from point to point now.

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Poor connection to the laps most likely created this. It's like a bottle neck in current. The weakest point will melt.

Ok, well what should i do with that

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Oooh , alright so if i change those metal holders that will actually help?

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Why iam asking because if i get luck and buy those somewhere will this happen again ?

[stj]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

if you desolder the holders you may be able to reverse the contacts so the burned side is away from the tube.

BUT the contact on the tube will also be burned.
so you need to sand the burned contacts to clean metal - fit the lamps - then solder the joints really.

btw, i'v never seen these before - only tubes soldered to long boards!

to answer your question - it will happen again because the tube contact is burned and the design is bad.

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Ok, u saying "solder the joints really " do u mean joints between the holder and tube ?
Sorry about this stupid questions but thats the way i learn
Thank you

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

I mean there is nothing to solder , those metal holders are in i plastic "bracket " and the lamps just slide there , also the side where the lams are is not burned , only the pins that goes to the actual board .

[stj]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

foto of the end of some lamps would help.

normally when a contact burns, both of the parts conected burn.

[freakaftr8]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Kinda redneck but you can always try soldering to the end of the lamp. Wear safety glasses.

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Ccfl

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

.....

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

.......

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

U can actually see that the holdet is not burn where the lamp slide in , its burn from the another side ... :/

[stj]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

no, the clips are burned a bit too.
the other side could mean it's a 2part clip and the burn is where they are spot welded together.

[stj]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

looking closer i see the problem.
atleast i think i do.

the pin on the bottom of the clip that goes through the pcb is too thin to handle the current.
that probably means the tubes are on the way out & drawing more current than intended.

all i can think of is soldering thick copper wire to each clip where the pin used to be.
use lead free solder - you'l probably need that higher melting point!

long term, a friend of mine replaced the tubes in a few backlit tv's using strips of leds that come on 5m reels from china - it works petty well.

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

Thank you so much for your time that help me a lot ...
Idea with diodes sound nice but i dont think i can do that :/
Anyway i will check it out today thx

[mr.mroz88]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

This is how the "holders " actually look

[budm]

Re: Sharp LC-52E77U no pic. Or sound found dead cockroach under power board HELP

OK, looking at your pictures, you have poor contact problem between the blade of the lamp socket, the C-clamp part of the socket that makes contact with the lamp is OK, it is the blade which shows black carbon marking is having problem making contact with black socket on the inverter board. You need to inspect those black sockets on the inverter board for contact corrosion/black carbon/burnt contacts. You need to clean the contacts real well.
Is this the inverter board you have?
http://www.shopjimmy.com/media/catal...tka529wjn1.jpg