Sony KDL-42ex440 went black and slight pop from speaker

[gates]

Last night my wife and I were watching tv and all of a sudden it turned off. We heard a slight pop from the speaker (residual sound going through speaker). Tried the remote and nothing. I unplugged tv and plugged back in, the power led turned green then pop it shut off again in three seconds (no back light).

I removed the back of the tv and checked out the power board and everything looked good, no bad caps and the voltages all checked out under power. When I unplugged the cable going to main board the led powered up, the remote allowed me to turn it on off standby. Plugged it back in and off it went again ith no controller.

Unplugged the Lvds cable everything went back to normal with the backlight and remote operation. So I am thinking bad T-con board.

Thoughts?

Thank you advance

Corey.

[newtothis]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Pictures of your boards and overall layout.

Voltage at Tcon fuse?

[gates]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Here is the layout and close up of the tcon board.

I check the fuse and could only get a slight voltage across when i plug it in for a second then it goes to zero

[budm]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Connect the LVDS cable back in place but leave the two flat white cables to the LCD out and see if the TV will turn on (there will be no pictures of course).
Also check the DCV of both ends of the fuse with ref to the chassis.

[sugar_ray]

Re: Sony KDL-42ex440 went black and slight pop from speaker

My money's on the PS board!! But dig a little deeper before replacement

[gates]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Lvds plugged in only and the green power light goes for three or so seconds the it shuts off. Residual pop sound through speaker.

I only get like two or so seconds to check voltage before it all shuts down.

[budm]

Re: Sony KDL-42ex440 went black and slight pop from speaker

So far I cannot find any service manual for this model.

[budm]

Re: Sony KDL-42ex440 went black and slight pop from speaker

http://assets.shopjimmy.com/media/ca...255-11-top.jpg

The white connector on the power supply board that goes to the main board has label for each pin that you need to take the DCV readings (no LVDS cable connected).
Report the readings with the name of the pin (names of the pins MUST be included) when TV is off and when power switch is activated so we can see what is missing.

[gates]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Power board with cable between it and main board unplugged. Plugged in power turned off.
Ac off det = 3.3 Vdc
Vcc 3.3 stby = 3.3 vdc
Everything else is zero

Lvds unplugged but main board plugged in with power board.
Standby (red light on) / power on (green led)
Panel power = 0v / 12.5v
Panel power = 0v / 12.5v
Audio 12v = .35v / 12.5v
Audio 12v = .35v / 12.5v
Vcc 12v = .35v / 12.5v
Vcc 12v = .35v / 12.5v
Ground = 0 / 0
Ground = 0 / 0

Ground = 0 / 0
Lcd pwr = 0 / 3.2
BLk err = 0 / 0
Bl central = 0 / 1.65
Blkt en = 0 / 2.92
Ac off = 3.3 / 3.05
Power onoff = 0 / 3.28
Vcc 3.3 stby = 3.3 / 3.3

[budm]

Re: Sony KDL-42ex440 went black and slight pop from speaker

"Lvds unplugged but main board plugged in with power board."
OK, they look normal when the LVDS is not connected.
So what do you get when the LVDS cable is also connected?

[gates]

Re: Sony KDL-42ex440 went black and slight pop from speaker

That is the problem it shuts off in two or three seconds. With the lvds cable plugged in and I plug the TV into an outlet the green power led is lit up and two seconds later it goes off and no power anywhere (also hear a residual sound through the speaker when the led goes off). No red led and no light coming from the led screen.

Any ideas on how to test this? Is there part of the ribbon cable I could test?

[budm]

Re: Sony KDL-42ex440 went black and slight pop from speaker

I have a feeling that something in the T-CON board is loading down the PANEL_POWER.
You may be able to remove just the terminals for the PANEL_POWER and see what will happen.
We also verify that the LCD panel itself is not loading down the T-CON because you have already try running the TV with LVDS connected but the ribbon cables between the T-CON and the panel disconnected and it still goes into shutdown.

This looks like your T-CON board:
http://www.shopjimmy.com/sony-1-895-...-con-board.htm

[gates]

Re: Sony KDL-42ex440 went black and slight pop from speaker

New tcon board then correct?

And yes that image is the tcon board I have.

[budm]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Yes.

[newtothis]

Re: Sony KDL-42ex440 went black and slight pop from speaker

My money's on the PS board!! But dig a little deeper before replacement

How much money were we talking here? :p lol

[vinceroger69]

Re: Sony KDL-42ex440 went black and slight pop from speaker

as sj is out of stock maybe this one?
http://www.ebay.co.uk/itm/Sony-KDL42...item20f4adf93d

[ReeceyBurger123]

Re: Sony KDL-42ex440 went black and slight pop from speaker

How much money were we talking here? :p lol

Lol

[gates]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Got replacement tcom board and we are back in action. Thank you everyone for the help.

[budm]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Thanks for the repair follow-up.

[fatcatbaz]

Re: Sony KDL-42ex440 went black and slight pop from speaker

Just out of interest, how much did it cost for the replacement Tcon board?