Sony 46EX400 won't turn on, 2 blinks

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

I have downloaded the 402 schematics, which I think it may be almost the same TV, but the European version.
The power supply seems the same at first glance.
Pages 24-25.

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

I'm measuring at the two secondary diodes D6151/6152 12.72V and at the T-con 12V there is only 0.092V all connected and .024V w/T-con disconnected.
Q6151 has the 12V in, but only the 0.092V comes out. It seems like it's a special FET transistor.
http://www.mouser.com/ProductDetail/...qZNnB2DIE1uU9X

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

OK, I look at the manual, on page 60:
2 blinks = power supply protection error
4 blinks = Balancer error
6 blinks = Inverter error
So it looks like we need to check the power supply section, not the inverter section.

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

That MOSFET is controlled by Logic transistor Q6152, you have to have >3VDC at T-CON on pin to get the T-CON 12V out, you had already indicated that you do not have the T-CON on signal at that T-CON on pin.
Is the POWER_ON signal is always there when the TV is powered on?

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

"T-CON_ON= -0.004v
T-CON_VCC= 0.092V
DIMMER= 2.96V
BL_ON= 0.046V
BL_ERR= 3.32V(TV ON OR OFF)
REG 12V= 12.71V
AUDIO 12V= 12.72V
POWER ON= 3.3V
AC_OFF_DET= 2.75V
STBY= 3.32V"

Can you monitor the BL_ON pin and the T-CON on pin when you turn the TV ON-OFF?

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

By the way, did the relay drop out?

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

What do you mean by drop out?

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

BL_ON is 0V when TV is off and 0.046V when the TV is on. When it turns off, it jumps to 0.2xxV and then slowly goes to 0V.
T-con_On is 0V when TV is off and -.001V when TV is on.
Power_On is off when the TV is off and turns on when the TV is turned on.
All these voltages go away as the protection kicks in.
I can hear the relay closing and opening when I flip the switch(short circuit tester w/bulb).

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

I would expect the BL_ON to go high >3v to try to start the backlights then I expect it to go off when it detects problem. The error detection will cause shutdown AFTER it detects problem first. So I would think all the normal signals should be present first to start the circuits, then go into shutdowN after the fault is detected.
Try it without the short circuit tester since you are not having shorted circuit problem.

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

The tester can affect anything?
I'm using it for convenience it has a switch.
I have tried it w/o, but made no difference.

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

Just do without it for now. We will have to do force on using the 1k resistors to feed the 3.3v pin to the POWER ON and the bl_on line pin to see if the lamps and the power supply will stay on, you will do it with the cable between the power supply and the main board not connected.

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

You mean to power both pins at the same time?

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

The STBY voltage is 3.3V. I still have to use a resistor?
Can I used my lab power supply?
I should apply the same voltage to the T-con_On too?

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

I have just put a jumper across Power_On and T-con_On and applied 3.2V to the jumper, but nothing happened.

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

"You mean to power both pins at the same time?" Use two 1 k resistors, one for the power on, one for the backlights on, no need to activate the T-CON, we just want to find out if the backlights will stays on and the relay also stays on.

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

I was trying to power the T-con_On in stead of the BL_On.
Unfortunately I don't have these resistors.
I don't understand why I need these resistors since stby is 3.2V?

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

Just a protection case you slip the connection directly to ground. There are resistor (1k) at the Power on and BL_ON (470 Ohm) pin already. So just be careful if you are not going to use any resistors.

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

PS stays on with backlight!
The SM from Dave is the same as the one I have posted in the first post.
In my opinion the second SM is pretty much(or exactly the same) the same.

[budm]

Re: Sony 46EX400 won't turn on, 2 blinks

So it does not go into shutdown?

[tibimakai]

Re: Sony 46EX400 won't turn on, 2 blinks

No. It stays on.