Mulja tv repair portal
Equipment Repairs => LCD TV forum => Topic started by: jimbofz on March 24, 2016,18:23:54
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Hi everybody ,this tv has the usual backlight off fault after a few seconds,( sound remains ok)
the error pin from the main board (comparitor type cct) which when tv is ok should be 0v, when it detects error it rises to 3v
which turns off backlight. so far no suprises,
but sometimes the pic from startup is ok then it goes off to black level and the backlight remains lit ,
i tried it on hdmi ,and aerial i/p ,when i tried the on screen menu ,menu was fine?
could it be i have more than one fault?
or is it likely to be one or more led ,just dont want to strip it right down untill im certain.
ive checked all the normal supplies are ok and no low esr caps this is the lg with the very slim boards with pencil thin electrolytics.
ive soldered the area around the mosfet led drivers ,this has a small green pcb mounted at the top of the psu which looks quite unserviceable,
it seems to me to be over engineered ,far to elaborate method of driveng the leds
anyone had similar fault?
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any comments i wont bite
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Hi Jim,
Looks like fun - Haven't yet had one in, but hoping - Chris.
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The error voltage is an indication of the non-functionality of the backlight LEDs. For it to generate this voltage, I'd say the LED voltage supply is OK.
Go on, be a devil, get that panel apart and have a Captain Cook at the LEDs. Bruce
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Ive had a few open ,but the thickness if it scares me ,
has anyone opened one of these super slim panels?
,i believe it has the leds down each side and a clever diffuser to illuminate the entire screen