sharp LC40ELE 600E standby only faulty backlight

[R_J]

Re: sharp LC40ELE 600E standby only faulty backlight

I suspect your meter is not reading the voltage across the led's correctly, The drive for the leds has a high frequency component and your meter is reading that as well as the dc value.

[jimbofz]

Re: sharp LC40ELE 600E standby only faulty backlight

any idea where i can buy leds for this model?
the working strips have 10 volts across each led
its model LC40LE 600E not as in title of post LC40ELE 600E
i know bl leds rely on constant current source,but the volts across each working led seems very high to me .any thaughts please
they dont have a built in zener

[jimbofz]

Re: sharp LC40ELE 600E standby only faulty backlight

d7519 has a low ohm resistor across it ,so my mistake.
any ideas why the original leds have 10v across them?
also tried many times to enter s/m no joy vol_ and source
simply dont work for me

[jimbofz]

Re: sharp LC40ELE 600E standby only faulty backlight

well foxit is great thanks
now i realise this is not the correct cct
my board has two plugs feeding the strips one with 10 connections one with 8 connections

i found d7519 s/c across it
its a zener .
lifted one end and diode is good
my psu is RUNTKA 609WJQZ

[jimbofz]

Re: sharp LC40ELE 600E standby only faulty backlight

thanks will give it a try

[diif]

Re: sharp LC40ELE 600E standby only faulty backlight

I don't know what PDF viewer you're using but in Foxit, pressing Ctrl and then the + key will zoom in making everything readable.

[jimbofz]

Re: sharp LC40ELE 600E standby only faulty backlight

the s maual is full of info
except the cct diagram is not readable
i wanted to check the components around the led driver ic
but simply cant read them

[jimbofz]

Hi this sharp was stuck in sby 5v sby volts present.
after the usual checks i jumped the psu with 470ohm to panel on and 5v sby to power on .
all supplies came up 12v etc ,
so after trying many times to get it to start in s/mode vol_ and source, then powering on no luck
the sby led remains red and not even a flicker from remote control
i decided to open up to inspect the leds
i found two s/c and 3 would light fine
but had lower resistance when checked
as my meter on diode test mode would not provide enough voltage for them to light i decided they must be 6v types as used on many lg models
once replaced each strip would light fine with my led tester
i was very suprised to find 10v across each of the original leds!
i assumed the leds were either 3v or 6v with psu forced on leds would only flicker
there are 9 strips with 17 leds on each all strips are individually fed from psu
with my led tester each strip has 170v across it
as youve guessed it
once re assembled without lcd panel and removed 470 ohm and link
symptoms remain the same refitted lcd panel still the same
now im at the head scratching stage