Sony KDL-46EX400 2 blink error code

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

I have checked a couple of those components and they didn't appear bad.
So no luck with that find. It may help somebody else in the future.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

To tell you the truth, I don't know what to do next.
I can't flip over the board to do those measurements.
What I'm noticing is that with the old board, the 12V won't stay on as with the one from Ebay. They turn on(except the T-con 12V) and then off.
The AC_OFF_DET= 2.77V, not getting higher.
Audio 12V and the Reg_12V they both turn on, but then off.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

I have just used a 1k resistor and a 2.2k resitor to boot up the PS and I have backlight.
The T-con voltages are still missing though.

[tom66]

Re: Sony KDL-46EX400 2 blink error code

T-con volt may or may not be switched by main board.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

It has a T_ON pin on the connector.

[budm]

Re: Sony KDL-46EX400 2 blink error code

The T-ON pin is the receiving pin which gets its ON command from the main board.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

What should be the next step?
It could be something with the Q6151, Q6152, Q6554 area?

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

Should I try booting up the T_Con_ON with another resistor?

[budm]

Re: Sony KDL-46EX400 2 blink error code

You can use the 1k resistor on the T_ON and the STBY voltage to force on the 12v T-CON but you have to disconnect that wire which goes back to the main board because the out put may be stuck in grounded mode. You can see that in the SCH that I had redlined.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

It's disconnected right now.
I have a 1K resistor going to the PS_ON and another one to the BL_ON. A third one will go to T-Con_On.
I will try it out tomorrow.
I guess, if it will turn on, then I have a bad mainboard and if not, then I have an issue at the T_Con 12V stage, am I right?
Thanks.

[budm]

Re: Sony KDL-46EX400 2 blink error code

If the 12V does not present at the 12v T-CON pin, then that may be the reason for the error code, the service manual keeps mentioning about 12V power supply failure. There is not much in that section of T-CON power supply.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

The other 12Vs turn on, only the T_Con 12V doesn't turn on.
I will try it out when I can. Right now my lower back flared up.

[budm]

Re: Sony KDL-46EX400 2 blink error code

Q6151 power MOSFET is being used as a switch to supply the T-CON 12V, if you short the E and C of the transistor Q6152, that will turn on the MOSFET Q6151, you can force it on that way also instead of using the 1K to feed the B of Q6152 to turn it on.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

I will do that, I don't have another 1K resistor.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

I have used the 2.2K which I have used to start up the BL.
T_CON 12V it shows 12.73V.
So the power supply is good, no?
I need another main board right(the third one on this TV)?

[budm]

Re: Sony KDL-46EX400 2 blink error code

That means some how the new board also failed to send out the T_ON signal.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

What I don't understand is, why every time I get a "new" board, it works for a while and then doesn't turn on, on an another day?
I update the firmware too, to the latest one available.

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

There is a way to reset these mainboards? Clear the error log?

[tibimakai]

Re: Sony KDL-46EX400 2 blink error code

Before I'm going ahead to buy another mainboard, I would like to ask a question.
The 12.73V is not to high to damage something in the mainboard?
It's just weird, that two boards have the same symptom, not counting the original board.

[tom66]

Re: Sony KDL-46EX400 2 blink error code

On a 12V rail, that is fine. If it were 15 ~ 20V, damage could occur.