NEVIR NVR-7402-40HD-N no standy by light

[mi16rs]

Hi

i have a NEVIR NVR-7402-40HD-N whit powersuply board CQC13001103908
the tv as no stanby light and wont turn on , i find a Diode faulty and replace it but still the same , i dont have any electric schem for it , could some one help me whit this ?

Thanks

[nomoresonys]

Re: NEVIR NVR-7402-40HD-N no standy by light

Test the powerboard to see where you stand, video demo there: https://www.youtube.com/watch?v=XH9GfkGQX1I

[nomoresonys]

Re: NEVIR NVR-7402-40HD-N no standy by light

Some straight on focused pictures of the whole back and of each board would help a lot.

[mi16rs]

Re: NEVIR NVR-7402-40HD-N no standy by light

Hi

Sorry for the late reply , in attachments are the pictures off the board

the diods mark in red one of theme was faulty so i replace it but still not work

i have meseured the voltage on the white conectors and it as no power so the problem on power suply but im not able to manage were the problem is , the main fuse is ok .

please could some one help me on this ??

Thanks

[nomoresonys]

Re: NEVIR NVR-7402-40HD-N no standy by light

It usually starts with powerboard testing, you have a multimeter? did you look at the video I linked? here's another: https://www.youtube.com/watch?v=4v8DcqCNG4A

[mi16rs]

Re: NEVIR NVR-7402-40HD-N no standy by light

Yes i have measure the voltages on the white conectro that goes to the logic board and i dont have any voltage on it

[nomoresonys]

Re: NEVIR NVR-7402-40HD-N no standy by light

Ok, unplug everything all connectors from the powerboard, plug power cord back into powerboard, see if you have the standby voltage.

[mi16rs]

Re: NEVIR NVR-7402-40HD-N no standy by light

i did that already and still no standby voltage

[nomoresonys]

Re: NEVIR NVR-7402-40HD-N no standy by light

Picture of powerboard isn't very clear, need standby voltage or nothing's going to work, simple things first, test power cord for continuity, make sure fuse on powerboard is ok, if ok, maybe move on to check bridge rectifier.

[nomoresonys]

Re: NEVIR NVR-7402-40HD-N no standy by light

https://www.google.com/search?client...rB7gLLy6TwCw18

[nomoresonys]

Re: NEVIR NVR-7402-40HD-N no standy by light

Check all diodes and resistors, at least the bigger ones, the tiny ones are a pain to deal with and should make sure that it is a tiny one at fault before messing with those. If any test odd, take out of circuit and test again, can search for resistor color charts if needed.

[mi16rs]

Re: NEVIR NVR-7402-40HD-N no standy by light

Yes i have done that and its all ok , this board as a ac/dc converter LNK7666E but i dont know how to check if this is ok or this is the one its faulty .

[dskall]

Re: NEVIR NVR-7402-40HD-N no standy by light

Hi

Sorry for the late reply , in attachments are the pictures off the board

the diods mark in red one of theme was faulty so i replace it but still not work

i have meseured the voltage on the white conectors and it as no power so the problem on power suply but im not able to manage were the problem is , the main fuse is ok .

please could some one help me on this ??

Thanks

Can't zoom on picture. Center white connector is 12v? What voltage do you have on main capacitor? Your mosfet on aluminum heatsink has a diode that is connected to drain of your mosfet. What is voltage across that diode?

[mi16rs]

Re: NEVIR NVR-7402-40HD-N no standy by light

only the blue mark conector as the stanby cable on , the red ones does not have anything conected , as for the main capacitor voltage this is a 100uf400v and i read 300v

[dskall]

Re: NEVIR NVR-7402-40HD-N no standy by light

Does white connector in center of board say power upgrade? Your pictures aren't good enough to see.

[mi16rs]

Re: NEVIR NVR-7402-40HD-N no standy by light

its not a mosfet its a LNK7666E ac/dc converter

[mi16rs]

Re: NEVIR NVR-7402-40HD-N no standy by light

see iff helps

[dskall]

Re: NEVIR NVR-7402-40HD-N no standy by light

its not a mosfet its a LNK7666E ac/dc converter

Looks like diode next to switching controller. What is voltage across it?

[mi16rs]

Re: NEVIR NVR-7402-40HD-N no standy by light

do you mean the one is mark in red??? puting the multimeter on it in DC does not show any voltage

[dskall]

Re: NEVIR NVR-7402-40HD-N no standy by light

If one end is connected to last pin on controller and measuring across diode shows no voltage, then I would say you have bad controller.