Sony KDL40EX400 having trouble powering up

[Phydoux]

I have a Sony Bravia KDL40EX400 that is trying to turn on. When I plug it in the tv comes on, Sony comes on the screen for about one second, makes a chime sound, and then it repeats 3 times. After that the power LED blinks 6 times. I disconected the 2 connections on the power board one at a time and got nothing each time. What I've read online is that it's a bad power supply. Any thoughts on this would be helpful.

[budm]

Re: Sony KDL40EX400 having trouble powering up

You should download the service manual:
http://elektrotanya.com/?q=showresul...oria=&kat2=all

AZ1K Chassis training manuals:
http://elektrotanya.com/?q=showresul...oria=&kat2=all

6X Blink - Backlight System Failure (32” & 40” Models)
NOTE: All models will make three attempts to power up before a 6X error is activated. The SONY logo (Backlight) will display on the screen and the tones (with Volume up) will be heard three times. After the third attempt the TV will turn off and the Standby LED will blink a 3X protection mode.
In most cases, if the backlight momentarily illuminates and the TV shuts off and a 6X is activated than one or more of the backlight lamps are defective. The LCD Panel assembly panel must be replaced for a defective lamp.
If a 6X blink pattern is activated than a defect has occurred in one of the following areas.
• Defective Panel Lamp(s)
• Defective Backlight Inverter Board
• Defective TV Microprocessor
• Defective 24V Power Supply
When troubleshooting a 6X backlight system failure it is key to notice if the backlights illuminate before the TV shuts off. The following list shows the possible backlight status and blink pattern and the possible failed components.
1) Momentary Backlight and 6X
a) Defective Lamp(s)
b) Defective Backlight Inverter Board
2) No Backlight and 6X
a) Defective TV Microprocessor
b) Defective 24V Power Supply
c) Defective Backlight Inverter Board
IMPORTANT: Before replacing the LCD Panel assembly check the backlight Inverter Board outputs. A failure of one of the inverter outputs will also cause this same symptom (Momentary Backlight & 6X).
If there is no backlight before the TV shuts off and activates a 6X, than check the “Backlight ON” signal from the TV microprocessor and the 24V power supply from the G2LE, G2HE, GD2-Board.
If the “Backlight ON” and 24V power supply are okay than the Backlight Inverter board has failed and must be replaced. This will be a rare occurrence but the Inverter board can cause a “No Backlight” condition and must be considered.

[tibimakai]

Re: Sony KDL40EX400 having trouble powering up

Thanks Bud for this manual. I didn't have this one.
I still have to fight with the 46EX400 2x blink error. Changed the T-con and still won't start up.
Now with this manual, I get check some more.

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

Yes! Thanks for all of that info and the link. I appreciate that VERY MUCH!!!

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

OK, got the replacement power board today and that doesn't appear to be the problem. It still does the same thing it was doing before. I am now thinking that it is the main unit where the problem lies. The only other board in this TV is the IR Control board and I don't think this would keep it from powering up...

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

There is also a TCON board I need to do a little more research on it.

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

Hmmm. This is interesting...

The LCD Panel Assembly includes the LCD Panel, TCON Board (300 & 400 series models), TCON/HFR Board (500 series models), and CCFL Backlight system.
The LCD Panel contains the actual liquid crystals, color filters, and polarizers. The liquid crystals are manipulated by the applied voltage to pass a specific amount of light - from the backlight- depending on the level of voltage applied.
The TCON performs all the control, timing, charge, and discharge functions driving the operation of the LCD Panel. The HFR (High Frame Rate) section performs the 60Hz to 120Hz frame refresh rate conversion.
A replacement LCD Panel assembly from parts will include the following items.

The TV comes up and says Sony for a second or two then appears to reboot and run this sequence a total of 3 times then gives me a blinking light which blinks 6 times.

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

Grrrrr

[tibimakai]

Re: Sony KDL40EX400 having trouble powering up

Did you check the tubes inside the panel?

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

I haven't dug that deep inside of it yet. Ill look at that tomorrow but if the tubes are bad then i shouldn't see anything. Correct?

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

Ok. I was able to look at this tv again this morning. I removed the rear cover and plugged it in and powered it up. Looking at the back I can see that all of the bulbs appear to be coming on. So it is safe to assume that it must be a bad inverter board. I think I might try ordering an inverter board and see if that does the trick. I've already tried power supply capasitors and a new power supply with no change.

If a 6X blink pattern is activated than a defect has occurred in one of the following areas.
• Defective Panel Lamp(s)
• Defective Backlight Inverter Board
• Defective TV Microprocessor
• Defective 24V Power Supply
When troubleshooting a 6X backlight system failure it is key to notice if the backlights illuminate before the TV shuts off. The following list shows the possible backlight status and blink pattern and the possible failed components.
1) Momentary Backlight and 6X
a) Defective Lamp(s)
b) Defective Backlight Inverter Board
2) No Backlight and 6X
a) Defective TV Microprocessor
b) Defective 24V Power Supply
c) Defective Backlight Inverter Board
IMPORTANT: Before replacing the LCD Panel assembly check the backlight Inverter Board outputs. A failure of one of the inverter outputs will also cause this same symptom (Momentary Backlight & 6X).
If there is no backlight before the TV shuts off and activates a 6X, than check the “Backlight ON” signal from the TV microprocessor and the 24V power supply from the G2LE, G2HE, GD2-Board.
If the “Backlight ON” and 24V power supply are okay than the Backlight Inverter board has failed and must be replaced. This will be a rare occurrence but the Inverter board can cause a “No Backlight” condition and must be considered.

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

I got the new board today. Got it installed and powered it up and worked fine. I programmedthe remote, turned the tv off with the remote, turned it back on with the remote and it's doing the same thing it was doing before. It ran fine for about 20-30 minutes. Now we're back to square one.

[tibimakai]

Re: Sony KDL40EX400 having trouble powering up

I have a 2x error code on my 46" and every time I get a maiboard, the TV would run for a while and then after a while it goes back again to 2x error code and it won't turn on anymore.
I don't know what else can be the problem?
I have tried from a working TV(same exact TV) the power supply board and it didn't change anything, I have even got another T-con board, which didn't help either.
The only way I can turn it on if I get a "new" mainboard.
I don't know what else can I do with it. The thing that makes me nervous is that I have repaired another 46"EX400 by replacing the mainboard. It had the same exact 2x error code. I hate repairing Sony TVs.

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

From what I can see on the back side, all of the lamps appear to be coming on. Did the new inverter board die on me that quickly? It's not new. I bought it used. It did work, as I mentioned, briefly.

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

Interestingly enough I thought before I shove this thing back in the closet I might try reseating the inverter board. Well, if I pull it out about a mm or 2 the tv works fine. However, now the screw holes don't line up anymore...

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

Temperamental POS. I jiggle the board, it works fine. Turn the TV off and I have to jiggle the board again... do i need to replace a lamp or lamps due to bad contacts?

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

I'm thinking the board could also have some flaws.

I tried installing the original board but it doesn't work at all. That board id decisively dead. I am sure this one is almost dead.

[freakaftr8]

Re: Sony KDL40EX400 having trouble powering up

You have a bad connection to where the inverter connects to the lamps. Look for burns or arc marks on one or more contactor.

[Phydoux]

Re: Sony KDL40EX400 having trouble powering up

On the board or on the lamp connectors themselves?

[freakaftr8]

Re: Sony KDL40EX400 having trouble powering up

Both. Take a good pic of the contacts connection points to the lamps