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Hello
I have on my table this sony kdl32ex600 with backlight issue. It's a common failure of this psu but i do not find any part faulted on this board.
The schematic it is almost the same, with minor differences with GE3B found at page 56 on this service manual:
https://elektrotanya.com/sony_kdl-32ex600_kdl-40ex600_kdl46ex600_chassis_az1-k.pdf/download.html
Uploaded only the page 56 from this sm to easing the search.
The red led it's flashing 2 times, meaning psu faulty. Indeed the led backlight does not light.
With the PSU outside of the tv, just with one resistance of 180ohm between standby ( pin 1 3,3V on connector CN6150 ) i get this values
on in:
starting with pin 1

1  +3,3V ST-BY
2  +3,3V AC_OFF_DET
3  +3,3V POWER_ON (with resistance 180ohm between pin1 and pin 3)
4  +12,56V AUDIO_12V
5  0V AUDIO_12V_GND
6  0V REG_12V_GND
7  0V REG_12V_GND
8  +12,6V REG_12V
9  +12,6V REG_12V
10  +0,1V BL_ERR
11  +3,3V BL_ON
12  0V DIMMER
13  0V DIMMER_DC
14  0V T-CON_Vcc_12V
15  0V T-CON_ON
All measure done at secondary ground point C6800 GND as reference.
Meanwhile, the led connected to CN6800 will remain with no light at all. The CN6800 will deliver positive 91V.
The negative branch will deliver at CN6801 ( both pin1 & 2 ) just -1V.
In the training manual found always in here at
https://elektrotanya.com/sony_kdl-32ex600_40ex600_46ex600_chassis_az1k_training%20manual.pdf/download.html
at page 56 will say "SHORT" at pin 12 DIMMER for testing the PSU, always with pin 3 POWER_ON connected to 3,3V ST-BY - pin1.
If i'll put a 180ohm resistance between GND and pin 12 DIMMER, then the tension on CN6800 will rise to +179V and the negative from the CN6801 will rise to -5V, the backlight led will light very very weak.
All tension from CN6805 will remain the same, except the BL_ERR will rise from +0,1V to +1,1V.
With only power_on pin 3 shorted by 180ohm resistance to the pin 1, i get this weak oscillation at emiter of Q6816 + Q6817

[URL=https://picturepush.com/public/16067400][IMG]https://www1.picturepush.com/photo/a/16067400/640/diverse/Q6816Q6817.jpg[/IMG][/URL]

With pin 12 DIMMER shorted ( always by a 180ohm resistance ) at GND, the oscillation will change from 250khz 1,6vpp to almost 70khz at 0,81Vpp. as below:

[URL=https://picturepush.com/public/16067401][IMG]https://www1.picturepush.com/photo/a/16067401/640/diverse/20181117-175255.jpg[/IMG][/URL]

Already checked the capacitors C6828 / C6830 together with D6805 / D6806.
Also checked the L6800 ( trafo ) and i've get 5,5mH instead of 5mH, i think it's ok.
All fuse checked, ok.
Q6814 and Q6801 tested under mosfet tester, ok.

[url=https://picturepush.com/public/16067402][img=https://www1.picturepush.com/photo/a/16067402/220/16067402.jpg][/url]

IC6800 & IC6801 gave +9V and respectively +2,49V

Already checked various components all over the board, i am out of ideas.

Any idea or help would be apreciated.
 

Sziasztok! Ezt a TV-t javítanám meg ha lehetne. A hiba jelenség: a nagy fesz, fűtés meg van, +200V meg van de sajnos képet nem ad. V-drive IC nagyon melegszik nem tudom hogy ez gond-e, indításnál a stby LED felvillan, ha kezelő panelen meg nyomok egy gombot el kezd villogni de semmi rendszert nem látok a villogásában.(hibakód stb) Csak újra indítás után hagyja abba. Kivéve a V-drive IC-t akkor normális a táp indulása. el képzelhető hogy ez kuka? Vagy rossz helyen keresgélek? Üdv István

Rövid működési idő (1-20 perc) után nem reagál sem a távra sem a nyomógombokra (a táv jelét veszi, zöld led felvillan). A hang és kép rendben megy még egy ideig, majd újraindul.
Kondikat végignéztem ESR-re, rendben vannak.
Merre keresgéljek? Köszönöm!