Dead set on 46EX400 Sony Bravia US 110V

[Letsfixit]

Hello TV repair gods,

I am using this guide to troubleshoot which has me in the right direction, but I am stuck.

No Power/Dead Set (No RED Standby LED)
In a dead set condition there will be No RED Standby LED illumination in the Standby Mode (TV plugged into an active AC Outlet).
The following bullet list gives the possible failures for a “No Power/Dead Set” condition.
• Loss of AC Power
• Loss of AC-OFF-DET
• Loss of Standby 3.3Vdc
• Loss of REG12V
• Loss of Power-On
• Defective Main Microprocessor
The first step in troubleshooting a “No Power/Dead Set” condition is to confirm that 110ACV power from an active AC outlet is applied to the G2LE-Board, G2LE-Baord, or GD2-Board. AC power is applied to, and can be measured at CN6101 on the G2BE-Board or G2CE-Board and at CN6003 on the GD2-Board.
Next, check for the presence of the AC-OFF-DET voltage at CN6401/pin 2 or CN6150/pin 2. If the AC-OFF-DET circuit is working properly 3V should be measured. If the 3V is not present replace the G2BE-Board, G2CE-Board, or GD2-Board. If the 3V in not present either the main fuse or the main power supply IC6501 is defective. In either case, replace the power supply board.
After confirming the AC power and AC-OFF-DET, check for a defective Standby 3.3Vdc power supply IC6201. To confirm a defective IC6201 check the 3.3V secondary voltage at CN6401/pin 1 or CN6150/pin 1. As long as AC power is applied to the TV IC6201 should be active and outputting 3.3Vdc. If the 3.3V is not present then IC6201 is defective. Replacing the power supply board will fix the problem.
Finally, a “Dead Set” condition can be caused by a defective microprocessor IC400. The microprocessor outputs the Power-On signal which activates the switch Q6301 and IC6301 on the power supply board and passes the 19V from the Standby power supply to active the relay (46” models), PFC, and Main Power Supply IC6501. If the Power-On signal is not output after receiving the Power-ON command the power supply board circuits remain inactive and a “Dead Set” condition exists. The Power-On signal can be checked at CN6401/pin 3 or CN6150/pin 3. It should measure approximately 3.3Vdc If the measurement is 0Vdc before shut-off the TV microprocessor is defective. Replace the A-Board. If the power-on voltage is 3V before shutdown then the switch circuit on the power supply board is defective. Replace the power supply board.

Power supply board=APS-260 (CH)

I do not have any blinking lights anywhere.

I have checked the ceramic fuses and have scoured the board for any bad caps or charring. There is a very small white coming out of the post on a ceramic cap, but every board i have seen for this model has this same thing.

I have power coming into power supply

Pins V:

STBY 3.3v
AC_OFF_DET: 2.74v
PWR_ON 3.3V all the time does not matter if I hit pwr button or not.

I have not found 12V anywhere.

When I plug in the AC cord I get a single click. When I DISCONNECT the Main board, It does not click and I do not get any V at PWR_ON, but stby and ac_off_det stay the same.

According to this troubleshooting guide it is the Power Supply board. I just would like someone to confirm I am reading the guide correctly and that this makes sense.

If anyone has further testing I need to do let me know.

Thank you for help in advance!
Chris

[nomoresonys]

Re: Dead set on 46EX400 Sony Bravia US 110V

try unplugging the bl-on connector from power supply or main board, then turn it on n see if the backlights pop on, as always be careful working with power supply, HIGH VOLTAGE, on primary side can be deadly.

[selldoor]

Re: Dead set on 46EX400 Sony Bravia US 110V

Are you wanting to do a component level repair or just trying to get an opinion on which board to replace. Have you read the stickies at the beginning of this forum

[Letsfixit]

Re: Dead set on 46EX400 Sony Bravia US 110V

I have read through the stickies on this section, I am really just trying to confirm that the power supply board is the correct board to replace. I also would be interested in knowing why that is the case.

nomoresonys- I get nothing when doing this.

Thanks for the quick responses.
Cheers

[budm]

Re: Dead set on 46EX400 Sony Bravia US 110V

If you do have ps_on signal, then you need to find out if you do have boosted Voltage or not at the two legs of the main filter cap.
The ps_on should not be present all the time, it should be >2.5V when power switch is activated, but some set will automatic turn on when power is applied.

[nomoresonys]

Re: Dead set on 46EX400 Sony Bravia US 110V

tristate has one for 68 bucks, coupon code up top of page for 10% off for new year, so about 62, make sure it's a match, can prob. call m, tell m your panel number and serial #, just to make double sure. http://www.tristatemodule.com/t-Search.aspx?q=46EX400+

[Letsfixit]

Re: Dead set on 46EX400 Sony Bravia US 110V

If what I believe the main filter cap is I am getting 22V AC constant even while hitting power button. I am getting power to Stdby(PS_on) 3.3V all the time.

[jetadm123]

Re: Dead set on 46EX400 Sony Bravia US 110V

Voltage across that cap is measured in DC Volts, not AC.

[budm]

Re: Dead set on 46EX400 Sony Bravia US 110V

Post 5 "If you do have ps_on signal, then you need to find out if you do have boosted Voltage or not at the two legs of the main filter cap."
You are checking the Voltage in the primary side so do not use the chassis as the GND ref. for your meter, and it is DC Voltage I am looking for on the TWO LEGS of the main filter cap.

[tibimakai]

Re: Dead set on 46EX400 Sony Bravia US 110V

If standby and power on signal is there and still no LED turns on on the bezel? That is weird.
I would rather think, that is a main board problem.
I have repaired two of these in the past, but they were blinking a 2x error code and both of them needed main boards. On one of them, took three boards, until it started working. I guess there are many bad boards out there.

[nomoresonys]

Re: Dead set on 46EX400 Sony Bravia US 110V

could try recapping the power board, looks like there arent really too many.

[budm]

Re: Dead set on 46EX400 Sony Bravia US 110V

If standby and power on signal is there and still no LED turns on on the bezel? That is weird.
I would rather think, that is a main board problem.
I have repaired two of these in the past, but they were blinking a 2x error code and both of them needed main boards. On one of them, took three boards, until it started working. I guess there are many bad boards out there.

I agree with that if his measurement are accurate since the Power indicator should come on or blinks with error code, and the PS_ON should not be stuck on all the time.

[masoodlodhran]

Re: Dead set on 46EX400 Sony Bravia US 110V

I have a sony klv-32ex400 with no power no led on in the set. please help/links to other post relates to it.

[anmol]

Re: Dead set on 46EX400 Sony Bravia US 110V

GD2 APS-260 1-881-519-21 Power Supply Inverter Sony KDL-46EX405 AZ1-L

wbr

[masoodlodhran]

Re: Dead set on 46EX400 Sony Bravia US 110V

Power Unit is G2LE

[budm]

Re: Dead set on 46EX400 Sony Bravia US 110V


You should start a new thread since it is not the SAME model as the OP.

[neilc6]

Re: Dead set on 46EX400 Sony Bravia US 110V

Have a 46EX400 with the same symptoms. No 12V, no front LED. While looking for points to probe PFC voltage (big cap legs not accessible from the top), I found R6536 (1/2W 0.47 ohm fusible resistor) blown. Could only measure 394VDC on one side. Searching this designator showed similar boards with Q6101 and Q6102 (2SK4096LS) potentially shorted. Waiting for parts from Digikey and will update once I've replaced them.

[budm]

Re: Dead set on 46EX400 Sony Bravia US 110V

There is a good chance that the IC output that drives the MOSFETs is damaged too so you ending up damaging the new MOSFETs if the IC is not replaced. You alo need to test all the parts on the GATE circuit too.

[neilc6]

Re: Dead set on 46EX400 Sony Bravia US 110V

Got the parts in today. Replaced R6536 (open circuit) Q6101 and Q6102 (both shorted gate to drain). TV is now working. Thanks budm for the heads up and anmol for the schematics.

[budm]

Re: Dead set on 46EX400 Sony Bravia US 110V

You are lucky with that shorts between Drain GATE, that Voltage could have been dumped back to Gate drive circuit.