Dead Vestel 17IPS71 power board

[fnets]

Re: Dead Vestel 17IPS71 power board

fantastic (yes can solder)

[vinceroger69]

Re: Dead Vestel 17IPS71 power board

this looks like the ic check on your board that it uses this ic it may not be faulty yet tests should prove either way
https://www.ebay.co.uk/itm/FAIRCHILD...cAAOSwc-tY3WfY

[fnets]

Re: Dead Vestel 17IPS71 power board

brilliant thank you. going through tests this morning starting page 1.

I'll probably replace the ic anyway but can't find anything similar to this on the board?

https://www.ebay.co.uk/itm/FAIRCHILD...cAAOSwc-tY3WfY

1. voltages across C19=325v, C20=324v, C21=324v
2. Diodes seem ok but ...

on diode setting my multimeter (Sealey MM19) shows 1 for open line. With -ve probe on grey band side I get a voltage. With +ve probe on grey band side I get voltage and then settles down to 1 after a few seconds. If useful I can detail the results for each one (but unsure how to identify other than referring to image)?

[vinceroger69]

Re: Dead Vestel 17IPS71 power board

the ic should be on the bottom of the board somewhere and diodes that read odd i just un solder one side lift it up from the board and retest. Im still learning myself so im hoping a more experienced member will give us some assistance to but for now do your best and follow this thread and run the tests suggested by the others.

[fnets]

Re: Dead Vestel 17IPS71 power board

I hope we can both learn something from this.

Here's my board



ic probably on the underside?



how do I test this? (also what does an led mosfet look like?)

[vinceroger69]

Re: Dead Vestel 17IPS71 power board

i hope so too the trouble is when we zoom into your pictures we cant see the part numbers etc on the ic s etc so it makes it hard to see what particular ic s etc are fitted on your psu can you try re uploading them maybe try this , click on go advanced then theirs a paper clip icon click on that and add your pictures that way.

[fnets]

Re: Dead Vestel 17IPS71 power board

the information of the ic is very small so it may be a problem but the one above has 6300A MYC on it (I can only just make it out). but still haven't found the problem so how do I test this (do I need it plugged in?)

[fnets]

Re: Dead Vestel 17IPS71 power board

re dick_barton above "So you have rectified DC so now to find out why you have no DC outputs". I'm going to check DC output again.

[dick_barton]

Re: Dead Vestel 17IPS71 power board

If you have no DC at the output then I would consider replacing the FAN6300A

[vinceroger69]

Re: Dead Vestel 17IPS71 power board

Thanks dick-barton you have more experience than i have in repairs, i did advise to replace that ic and added a link, but he could not find it on his board? hence i asked for better pictures so we could point out the ic.

[fnets]

Re: Dead Vestel 17IPS71 power board

help has been fantastic, thank you.

Have ordered a new FAN6300A

this is tiny, any advise on replacing.

[vinceroger69]

Re: Dead Vestel 17IPS71 power board

I hope we can both learn something from this.

Here's my board



ic probably on the underside?



how do I test this? (also what does an led mosfet look like?)

led mosfet i think maybe q17? bottom side of board hopefully dick-barton will advise although i think your issue maybe that fan6300 ic i sent the ebay link for

[dick_barton]

Re: Dead Vestel 17IPS71 power board

I think your mosfet to check out is Q15. Hard to tell from the pictures.
Check all the diodes around the FAN IC and the Mosfet

[vinceroger69]

Re: Dead Vestel 17IPS71 power board

I think your mosfet to check out is Q15. Hard to tell from the pictures.
Check all the diodes around the FAN IC and the Mosfet

The pictures in post 2 are zoom able and clear i first thought q15 then edited my post as wasnt really sure

[fnets]

Re: Dead Vestel 17IPS71 power board

can I ask what q15 means?

[vinceroger69]

Re: Dead Vestel 17IPS71 power board

on the board you have printing by each component q15 is the a reference designator, we think its the led driver mosfet you have been asking about earlier in the thread q basically means transistor like c then a number means its a capacitor r then a number is a resistor this link is quite good.
https://electronics.stackexchange.co...-markings-mean

[fnets]

Re: Dead Vestel 17IPS71 power board

ok thanks

this is q17



should I test this? (if so how)

[vinceroger69]

Re: Dead Vestel 17IPS71 power board

q17 yes thats the one i thought may of been the led driver mosfet but dick-barton mentioned it maybe q15 which is on the top side of the pcb under a black heat sink i think
this guide may help you
https://www.youtube.com/watch?v=RkWy1EirEu8

[Joba01]

Re: Dead Vestel 17IPS71 power board

Hi guys, thanks a lot for all the descriptions, it already helped a lot to understand the process and common falts. I have the same vestel board in a 'Telefunken' TV. The standby LED on the front is blinking. I tried all measuring than you described. On the CN4 output connector I read the 12 volt but I don't get the 5v standby voltage, any guesses what could be wrong? I also read 2.5v on pin7(the 4th pin in the upper row, starting from the pin that is marked as 1 on the board). I could't find a shorted diode, I still changed d22, d24 and d26 but that was more like last resort . The mosfet is a FDD120AN15A0, I tried to measure the DC voltage to ground it was 34v between source and drain and 34v between gate and drain, not sure how to interpret that. Hopefully you guys have a hint, best joba

[Calderon]

Re: Dead Vestel 17IPS71 power board

Hi, i have Finlux TV with this same powersuplly, measured between q17 drain and source and its shorted? Also when this is plugged in i hear very high pitched noise going louder about 2 secs and then silence for 3-4 sec and again, as itś trying to start or something.. this comes from the powerboard..?