KDL-40BX450 Not power

[enito]

Hi,
I have in my a big shorctu, where 2 LCD died. Now this one the sony kdl-40 i try to power on, and no luck. I opened the case and check powersupply and dont see any damaged component. I checked fusible and works no problem. I checked standby voltage (3v) and i get read. But when i check other points like 12V i dont get read. Now my question, PSU DIED? what can be the steps for try to found the damaged part?

thx for the time for read.

Greets
enito

[budm]

Re: KDL-40BX450 Not power

https://www.badcaps.net/forum/showthread.php?t=39740

We need to find out if the main board is sending all the needed signals or not.
Any blinking LED for error code?

[enito]

Re: KDL-40BX450 Not power

Hi thx for reply, no bliking , nothing react.

Late i take some photos of board, area voltages for guide me what measure i need to check. thx !!

[enito]

Re: KDL-40BX450 Not power

Btw, how i can check if maniboard is not damaged? i see and no burned or something.. how i can check if main is sending signal?

photos coming...

[budm]

Re: KDL-40BX450 Not power

Once we see the good clear pictures of the boards and can see if the connectors have any labeling on them or not to let us figure out what the pins functions are.

[budm]

Re: KDL-40BX450 Not power

BTW, there are more than one version of this power supply.
http://www.shopjimmy.com/catalogsear...?q=KDL-40BX450
Looks like the power supply fails a lot so there is repair kit for it.

[enito]

Re: KDL-40BX450 Not power

Hi, yes i see some replacement set, but wanna be sure if the psu was damaged or other thing. Here i attach photos of boards, i lifted resistor of psu for test. Thx for read















http://postimg.org/gallery/15o2mdc3k/20ce7685/

[budm]

Re: KDL-40BX450 Not power

I looks like the P/N on the board is BN44-00340A? If it is, it is SAMSUNG power supply board. See SCH of 340B.
http://www.shopjimmy.com/samsung-bn4...upply-unit.htm
Can you please verify?
340B is compatible with 340A so the pin out of the connectors are the same.
The board has pull-up resistor for the POWER ON/OFF (PS_ON) and the BL_ON so you can disconnect the cable between the power supply connector CN802 and the main board, then plug the TV into the outlet the backlights should come on right away, if it does then the power supply board is OK.
BTW, what country are you in so we will know what the line voltage is?

[enito]

Re: KDL-40BX450 Not power

Hi, true, i show you the other one lcd damaged , samsung. Sorry..but this can help too let read your info.

[enito]

Re: KDL-40BX450 Not power

Chile, 220V

[enito]

Re: KDL-40BX450 Not power

Here i upload the Sony one (same fault, not power on)

http://postimg.org/gallery/2htm8sej8/4315628e/

thx again for your time!

[enito]

Re: KDL-40BX450 Not power

Ok read, now if i disconnect psu CN802 connect, how i can see if backlight is powered? cause the main board is going to be disconnect for send current to powerlight..sorry for no understand fine this point...thx!

[budm]

Re: KDL-40BX450 Not power

http://www.shopjimmy.com/sony-1-474-...g10-board.htm#

OK, take the DC voltage readings on each pin of the connector CN6401 when TV is plugged into the AC and when the power switch is activated, use chassis as the ground point for the meter. Make sure to list all the pin names follow by the Voltage readings.
For example:
Pin 1 (STBY 3.3V) = xxx V (TV OFF), xxxx V (TV ON)
Pin 2 (AC DETECT) = xxx V
Pin 3 (POWER ON) = xxx V
.....
.....
Pin 15 (T-CON ON)

[budm]

Re: KDL-40BX450 Not power

Ok read, now if i disconnect psu CN802 connect, how i can see if backlight is powered? cause the main board is going to be disconnect for send current to powerlight..sorry for no understand fine this point...thx!

Are you talking about the SAMSUNG? You should start another thread for SAMSUNG, so please concentrate on the SONY right now so I do not get confused trying to answer two different models at the same time/same thread.

[enito]

Re: KDL-40BX450 Not power

Sorry about this , i opened a thread about the samsung

https://www.badcaps.net/forum/showth...587#post479587 (backlight worked)

Now i check voltages of SONY one and i tell you about discover.

Thx!!

[budm]

Re: KDL-40BX450 Not power

OK, it is late for me now, I will check back tomorrow.

[enito]

Re: KDL-40BX450 Not power

Sure, now i check voltages and dont get good read, like pin 1 0.3v , is like power button not working, cause no power led nothing...

[budm]

Re: KDL-40BX450 Not power

Right now there is no standby voltage so we need to look at the standby power supply section.

[withalligators]

Re: KDL-40BX450 Not power

I had a 46bx420, totally dead, no power LED or anything. Naturally, I thought this was a power supply issue, but after much frustration, it turned out to be a mainboard issue. replaced the mainboard for about 50 off ebay, I gave it to my Girlfriend, and it is still working today.

Cheers,
Alex

[enito]

Re: KDL-40BX450 Not power

Right now there is no standby voltage so we need to look at the standby power supply section.

I see , and where is the area? and i thinked, what about eeprom fault (if this one have). I read in samsung can make some bridge in pins for reset, or apply with some codes factory restore. Not sure if this one can work, but i dont have codes for factory restore.

thx again