LCD TV won't turn on. LED keeps blinking

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

do i test the 450v cap again?

[vinceroger69]

Re: LCD TV won't turn on. LED keeps blinking

yes put the psu back in the tv connect it all up as how it should be and carfully test voltage across that capacitor again

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

320v in 450v cap
is it bad?

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

GND of primary and secondary circuits are not connected. Is it a fault ?

[vinceroger69]

Re: LCD TV won't turn on. LED keeps blinking

i would of thought it should be slighty higher when the pfc circuit boosts the voltage up although the 450v on the capacitor is the maximum it can take it does not mean it should be 450v ive been trying to find a service manual for the tv but no luck as yet hopefully budm will have a read of this thread and have a idea what too check next as im still learning myself too ive attached a data sheet for one of the ics in your previous posts but cant find a data sheet for the other on, so bear with us im sure a more experienced members will advise on some more tests you can run soon.

[culcuhain]

Re: LCD TV won't turn on. LED keeps blinking

make sure you are using the legs of the capacitor to check the voltages for the large caps.

[dick_barton]

Re: LCD TV won't turn on. LED keeps blinking

so you have fitted the new correct fuse to the psu then used the dim bulb tester and buld flashed and went off? if thats the case we can start testing voltages again we need to see why the boosted voltage is not there i have found a data sheet for the larger ic but cant seem to find one for the 230d6 ic

I believe that these are the data sheets needed.

[dick_barton]

Re: LCD TV won't turn on. LED keeps blinking

Are you able to confirm the DC voltage across the large capacitor when switched on out of standby.

[vinceroger69]

Re: LCD TV won't turn on. LED keeps blinking

im sure he tested that a few posts back now hes repaired the blown fuse it was 320v ive never worked on the pfc circuit so im still learning too from you guys as what too test next etc

[dick_barton]

Re: LCD TV won't turn on. LED keeps blinking

Test the voltage on the VCC pin of the L6559 very carefully.
The DC voltage between Pin12 (VCC) and ground (negative leg of large capacitor) should be 10 -11.5V at turn on with a maximum voltage of 16V

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

I checked the ic

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

yes i checked the legs of the cap.

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

thank you barton for the files

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

i checked the output pins and there is no voltage. (white pins)

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

Are you able to confirm the DC voltage across the large capacitor when switched on out of standby.

yes i switched on and tested the voltage. its around 325v

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

Test the voltage on the VCC pin of the L6559 very carefully.
The DC voltage between Pin12 (VCC) and ground (negative leg of large capacitor) should be 10 -11.5V at turn on with a maximum voltage of 16V

i checked the ic
VCC and the GND are connected (both are GND) :o
there are some issues i checked the board
a diode and transistor connected to GND line. (both sides)
i cant find, where is the short or the bad component.

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

both pins are GND

[vinceroger69]

Re: LCD TV won't turn on. LED keeps blinking

im not sure what your checking you need to test the ic by putting negitive multi meter lead onto negitive side of the large capacitor and then the red multimeter lead onto pin 12 of the ic and take the voltage reading be carfull not too let the probe slip as can short out small pins easily ive marked the ic you should be checking with a yellow outline

[sahan14]

Re: LCD TV won't turn on. LED keeps blinking

is it okay, VCC and the GND in the IC..... are both connected to common ground line?

[vinceroger69]

Re: LCD TV won't turn on. LED keeps blinking

see above edit ive made is that the ic your testing?