Sharp LC-40LE830M no power

[newtothis]

Re: Sharp LC-40LE830M no power

Yes

[chewbacca78]

Re: Sharp LC-40LE830M no power

it reads 0V

[newtothis]

Re: Sharp LC-40LE830M no power

Right.

So we have a few possible reasons,

So first check voltage at the main input ON the power board next to the fuse, If you have voltage there then either your test on the fuse was incorrect OR there is a broken joint either at the incoming side of the fuse or at the terminals for the Main input OR your meter/leads are faulty/set incorrectly

[vinceroger69]

Re: Sharp LC-40LE830M no power

how are you testing the fuse? just to check your doing it right

[chewbacca78]

Re: Sharp LC-40LE830M no power

Taking the black and red lines as the probes, i first place the probes at the ends of the fuse itself then at the wires.

[newtothis]

Re: Sharp LC-40LE830M no power

Confirmation of voltage at the connector next to the fuse when plugged in?

If you get voltage leave the negative lead at the connector and put red to right side of that fuse, Reading?

[chewbacca78]

Re: Sharp LC-40LE830M no power

voltage at the main input of the PSU measures 240V. I then place the red probe on both ends of the fuse and the black probe on the ground and measure both sides as 134.4V. Long capacitors still 0V

[chewbacca78]

Re: Sharp LC-40LE830M no power

it reads 240V with negative end at the connector and red at right side of fuse

[vinceroger69]

Re: Sharp LC-40LE830M no power

ignore please

[newtothis]

Re: Sharp LC-40LE830M no power

That is with meter on VDC with a probe to each leg of one capacitor correct?

[chewbacca78]

Re: Sharp LC-40LE830M no power

sorry my bad, both long capacitors measures 330VDC

[newtothis]

Re: Sharp LC-40LE830M no power

Ok lastly can we double check the STB voltage at the connector mentioned earlier please... As we have had inconsistencies in readings

[chewbacca78]

Re: Sharp LC-40LE830M no power

i got 0 VDC at the point circled red

[newtothis]

Re: Sharp LC-40LE830M no power

Ok this is the point a Schematic would be very handy but not finding one anywhere.

You will need to get a good clear photo of the underside of the power board so it is possible to see all traces and read and markings clearly.

I am useless at tracing out circuits so someone else will have to take it from here, our member budm is very good at this and hopefully he jumps in when he comes online.

Good luck

[chewbacca78]

Re: Sharp LC-40LE830M no power

hi newtothis, thanks for your patience and help in guiding me to check on my PSU. i'll have to continue tomorrow as it's almost midnight here in Singapore. Gotta rest now and work tomorrow. I'll remove the power board and will try to take a clear picture of it and hopefully budm will help me out with it. Thanks again

[chewbacca78]

Re: Sharp LC-40LE830M no power

Couldn't sleep without taking the pics...so here they are.
Any advice will be much appreciated. Thank you.

[tibimakai]

Re: Sharp LC-40LE830M no power

Do it outside, in sun light.

[tibimakai]

Re: Sharp LC-40LE830M no power

There is a secondary side of the power supply, marked with that thick line. You use the black probe on the mounting screw. On the primary side, the black probe, goes to the negative of those big capacitors.

[chewbacca78]

Re: Sharp LC-40LE830M no power

hi tibimakai, thank you for your suggestion but is it possible to circle on the board so I won't make any mistake as i'm a noob in troubleshooting tv. Thank you.

[chewbacca78]

Re: Sharp LC-40LE830M no power

Is there anybody who can help me with my problem? Thank you