Samsung LE37A656A1FXXU no sound or picture

[rbarsa]

Hello Guys,
I have problém with tv that won't turn on (similar like https://www.badcaps.net/forum/showth...hlight=samsung )
also when I plugged in stdby led is on, but when try to turn it on with remote led blinks five times, than led switch of and TV turns on but there's nothing on screen, neither there is samsung chime nor sound. I can see that set is responding on remote commands because led is blinking when some of keys is applied.
Few months ago I did replace the capacitors in power supply becuse of blinking issue which helps. Now all capacitors seems ok, thee is no more issue with 24V. The backlight remains off even there is 24V on and 5V on B/L ON-OFF.

Measurement on connectors shows as follow:
CNM 803
24V - 24,3V
A/D - 3,5V
B/L ON-OFF - 5,1V

CNM 802
ON/OFF - 3,4V
ST-BY - 5,2V
12,8 - 12,1V
5,3V -5,2V
12 - 11,6V

CNM 801
DET(5V) - 5,36V
A/D - 3,5V
P/D - 3,2V
B/L ON-OFF - 5,1V

The power board is BN44-00216A , the main board MT8226.

Please can you help - Thank you !!

[tom66]

Re: Samsung LE37A656A1FXXU no sound or picture

Since you have BL ON/OFF at 5V and 24V at the inverter, the fault is with the inverter. Can you supply pictures of the inverter, with the plastic shield removed? You can operate it temporarily without the shield.

[rbarsa]

Re: Samsung LE37A656A1FXXU no sound or picture

I checked both fuses and both are ok.

[budm]

Re: Samsung LE37A656A1FXXU no sound or picture

Check F1 (Black fuse with '20' printed on top), see if it shows <1 Ohm (unplug the TV when testing resistance). That black fuse is the commonly failed part. Also check F101, F301.
http://www.shopjimmy.com/media/catal...03101a-top.jpg

http://www.shopjimmy.com/auo-vit7103...t-inverter.htm

[rbarsa]

Re: Samsung LE37A656A1FXXU no sound or picture

Bingo - The F1 is blown off !! Thank you tom66 and budm for guiding !!
Do you know, what should be the replacement ? Is it common issue, when fuse replacement helps, or there is a reason and there is a deeper problém behind ?

[budm]

Re: Samsung LE37A656A1FXXU no sound or picture

I use PICO II fuse, 1A. No need to remove the old fuse. Just locate the pad that is connected to each end of the fuse to solder the new fuse in place.
http://www.digikey.com/product-detai...2319-ND/700725