Finlux 32FLD760P with Vestel 17PW20.v1

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Already did, 333, or around that sadly enough. Damn, well now we know it wasn't those caps either. Any suggestions?

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Hmm, I just found SM for your set, if it helps:-
http://www.tgohome.com/ServiceManual...&Search=Submit

OK, can you find C881? It'll be near one of these:
http://circuits.datasheetdir.com/39/NCV317-pinout.jpg
but not bolted to the heatsink, globbed down.

When you find C881 measure the voltage across it.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I think I found it, in the middle of the board. If looked at from the picture, furthest left and middle is -95v and right is -88v, but that is when I measure with chassis as ground. Or do you want me to do it some other way?

I used the red pin from the DMM, so I'm guessing it's supposed to be negative?

Edit. Here's a picture http://sparedparts.com/images/made/1...850_540_90.JPG. Mine had waaaaay more glob on it, couldn't reach pins very well.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

You need to measure across it. That is the right area.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

So like, pin 1 and 2, pin 1 and 3? I'll give it a try. Should the tv be on or standby?

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Across C881.
TV must be ON.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Sorry, it's just that the term measure across get's a little conflicted in translation, especially since I'm not very used to using the DMM

Edit. Would 6.8v be correct? I'm not really sure I'm meassuring this one right, it's really hard to see and reach too with the glob stuff around.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Positive DMM probe on positive leg of C881, negative DMM probe on negative lead of C881.

Your English is better than my Swedish. I know of approximately zero Swedish words.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Haha well, that because English is compulsory in schools

I measured 5.7v, I think, could be 5.1v too, the last digit on the DMM doesn't light up good enough but it's definitely 5v

Edit. It's 5.7v, figured I could change settings on the DMM.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

That's too low. I think it should be at least 9~10V, preferably more.

Edit: according to this calculator it should be 12.6V:
http://www.electronics-lab.com/articles/LM317/ (input 1k and 9.1k)

If the ON/OFF signal is on, it will drop to about 1.2V, but that's not what we are seeing, it's half way between the two.

Next step, do you think it's possible to measure between pin 1 and 2 of the LM317? Pin 1 is the leftmost pin, looking at the front of the device.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Wait, I think I did it the other way around. When measuring the leftmost pin it measures 1.2v?

If you look at the picture I linked, is pin 1 to the left or right when it's put in that way?

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Pin 1 is the leftmost pin, looking at the front of the device. (i.e. you can read the "LM317" label)

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Ok! Yup, pin 1 and 2 is 1.2v across

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

OK, IC811 crosses primary to secondary. On the two primary pins what voltage do you measure across them?

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Geez, 107v? Can that really be correct?

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

You need to measure the voltage between the two closest pins on the primary side.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Oh, yeah well then it's 0 or very close to 0v

Edit. I'm gonna head for bed, would be nice if we could continue this tomorrow but I understand if you're busy! G'night Tom, thanks for all the help.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I'll have a look tomorrow. Got 9am lecture, am going to bed now ...

[budm]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I look through my hard drive and found the sch that Tom or some one else has posted in the forum. Not sure which one is the correct one for your board.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

The schematic I am working off.


It's awful, such a mess, and the PFC controller is apparently a MOSFET, I guess that was a readily available footprint and they were too lazy to change it...