Can you dignose from the photo ? . Toshiba 65S2650EV

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Yes, a tv from hell, sadly.. i thought we there were... now, i was expecting more on pin 12 ic3, i don't know what there is between pin2 q10 and pin12 ic3, it seems pretty straight, only a 10 ohm smd resistor if i can see.. also another thing, if on opto UF1 cold side there is 1,2v then hot side must conduct and then q10 pin3 (i guess base) tied to gnd, test the hot side pins of UF1 it must be less than 1v, maybe q10 has an internal pullup resistor to the collector.. test the pin16 of ic3, must be a little lower than pin12.. have you tested outputs with PSU alone?

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Yes. I did not see any V on 12V . I recall seeing no V on Opto Cold side ? I must measure again.
q10 pin3 had 12.6V
I will investigate everything and provide as much data as I can.

I need time to decipher what you wrote, because , having little knowledge I need to think how it works etc. tomorrow

What puzzles me is that the problem that "started" with blown fuse , bridge and wire resistor has now moved to the Cold Side ? what could it be ? Is it possible it came from Mainboard ?

Thank you very much for staying with me on this TV.

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

The profile of this tv is of a tv that is been hit once by an heavy spike from the mains, but the faults are been revealed one at the moment, others delayed, sometimes it happens..
forget the previous post, to make it simple, test only the pin16 of ic3, must be a little lower than pin12..

PS: the faulty AZ431 is due to the fact that the spike trespassed the optocoupler and hit that.. maybe you can try to put on the 5vsb output a dummy load like 3ohm 2w.. if the tension collapses under 5v then standby psu has something not good in feedback still..

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Pin 12 : 9.62V
Pin 16 : 9.47V

5VSB is 7.42V ! under [10 Ohm 5W] load it remained stable for ~ 7 seconds.

Where is the Standby PSU on the board ?
Should I check Mosfets under HS on Cold Side ?

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

neghter the mosfet nor diode are the problem, maybe the 6pin controller, but after 7 seconds?

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

is it possible that you grabbed a bad 431 chip from other psu? Are those psu ok?

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

I figured 7 seconds are enough. 6pin, IC2 controller unrelated, I didn't check it.
Not from good PSU.
I replaced from a good one and still get 7.4V on 5VSB

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

ic2 doesn't matter, ic1 is the one... i think your tester battery is low, have you got a new one?

[lotas]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

It looks like the R37 resistor has burned out.

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

..

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

OK
I replaced the Opto and the "transistor" IC : 817 and 431 , with new ones. AZ431 , EL 817

I took out R37 .. asking for trouble.. I knew it..
puff .. gone !
and found after vacuuming the whole area
I put it on masking tape : measures 123K . Its marking is 562 = 5.6K !

* I tested my DMM : with 4 AA batteries and SMD Resistors ( which are easy to know the value of ) : my DMM is fine

Now I am looking for new 5.6K SMD

[lotas]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

If the resistor burns out, then most likely the NCP1653A also burned out.

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

OK. Got the datasheet.
I'll look for shorts. and new R37

But FYI , we got 5.2 on 5VSB Pin at first ( no PSU High V output ) , and after changing the Opto and IC : 817 and 431 : we got 7.2 . Thats for standby V

[lotas]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

So put the native 817 and 431 back in place.
"431" comes with a different pinout

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Found R37 Resistor 562 . But smaller - see image.
Would it burn

haven't checked yet for shorts on NCP1653 = IC2.

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

No, don't put original ones! We are not shrimps the original 431 is faulty, and sorry i thought AZ431 was same as TL431 to simplify things but them are not same, the change ratio vref/vka is different, this why you have wrong Vout, i apologize, i'm very sorry.. get a true Az431.. if you don't have connected mb with this bad Vstby no damage..

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

No, don't put original ones! We are not shrimps the original 431 is faulty, and sorry i thought AZ431 was same as TL431 to simplify things but them are not same, the change ratio vref/vka is different, this why you have wrong Vout, i apologize, i'm very sorry.. get a true Az431.. if you don't have connected mb with this bad Vstby no damage..

I put AZ and 817 Opto from another source.
I am searching for "same size" R37 5.6k Ohm SMD , and another IC2 NCP1653

I don't remember, but I might have connected Main... hehe looks like this TV doesn't want to be repaired isn't it ?

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

is the face of 431 facing the hot side? if yes so you have probably a bad ic1, to mention that i usually don't have seen any transistor near the 431 area and i ignore its function, maybe check it for shorts..

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

is the face of 431 facing the hot side? if yes so you have probably a bad ic1, to mention that i usually don't have seen any transistor near the 431 area and i ignore its function, maybe check it for shorts..

I don't quite understand : U3 AZ431 is (flat) facing out from the separation line
IC1 ? where is it ?
check what for shorts ?

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

i was asking if you have put attention to the right rotation of the AZ431, forget the rest, i think we are going quite to a dead rail.. i don't understand why these strangenesses.. there are not much components to test in a feedback..