Dead Vestel 17IPS71 power board

[budm]

Re: Dead Vestel 17IPS71 power board

no voltages at all at CN3/4 connector

May I ask what you use for GND ref. for your meter?

[dick_barton]

Re: Dead Vestel 17IPS71 power board

Please watch my video, yes its a different Psu but same concept:

https://m.youtube.com/watch?v=owmBcJ91yJw

+1 He needs to have some idea of process so a good suggestion.

[ReeceyBurger123]

Re: Dead Vestel 17IPS71 power board

+1 He needs to have some idea of process so a good suggestion.

Cheers, hopefully helps him out. Does save alot of time typing things up

[london-freddie]

Re: Dead Vestel 17IPS71 power board

yes checked them all seem ok

[ReeceyBurger123]

Re: Dead Vestel 17IPS71 power board

So the diodes with your meter in diode mode do not beep ? Also what about the Led mosfet
.

[ReeceyBurger123]

Re: Dead Vestel 17IPS71 power board

If the Led mosfet is good put your black probe on chassis ground and then see if you have 5v and 3.3v at the Ir sensor (pins 2 and 3 of the sensor) which is mounted on the front frame of the Tv, if so the Psu if fine and your motherboard has failed.

[london-freddie]

Re: Dead Vestel 17IPS71 power board

to the best of my knowledge and ability and after watching the video
diodes seem ok led mosfet seems ok and no voltage at Ir sensor

[budm]

Re: Dead Vestel 17IPS71 power board

What is the P/N of the SMPS IC U202 in the primary side?

[london-freddie]

Re: Dead Vestel 17IPS71 power board

Te5an
6300a
myc

[dick_barton]

Re: Dead Vestel 17IPS71 power board

Data sheet:

[budm]

Re: Dead Vestel 17IPS71 power board

OK, FAN6300 SMPS IC.
Check the DCV between GND pin and HV pin, GND pin and VDD pin.
Be real careful you are working in the deadly side of the circuits.
BTW, this power supply is has an always on 12VCC and 24VCC power supplies per SCH by DB.

[london-freddie]

Re: Dead Vestel 17IPS71 power board

ok checking FAN6300
GND and HV 80V
GND and VDD zero volts

[dick_barton]

Re: Dead Vestel 17IPS71 power board

With your meter set to 20V can you measure VDD again and see if there is a voltage present immediately on switch on that drops suddenly.

[ReeceyBurger123]

Re: Dead Vestel 17IPS71 power board

You should have 24v and 12 on the output side of the secondary side diodes, do you have that ? If not sounds like something on the primary is up.

[dick_barton]

Re: Dead Vestel 17IPS71 power board

I think the Fan6300 must kick in and drive the Mosfet Q15 for the dc supplies to come up.

[london-freddie]

Re: Dead Vestel 17IPS71 power board

no voltage at VDD on start up at all

[dick_barton]

Re: Dead Vestel 17IPS71 power board

Can you check Q15 with your meter set to diode mode. Set switched off.
https://www.youtube.com/watch?v=gloikp9t2dA

[london-freddie]

Re: Dead Vestel 17IPS71 power board

can not find any voltages anywhere on the cold side

[budm]

Re: Dead Vestel 17IPS71 power board

Check the resistance of R289, 290, 291.
From looking at the picture, it looks like it has '393' printed on top.
Also check the resistance between VDD pin and GND.

[london-freddie]

Re: Dead Vestel 17IPS71 power board

what is easiest way to check Q15, watched the vid but not making much sense to me if i am honest