Sony Bravia KDL-46EX723 - 4 blink code

[Toasty]

Got this in from a friend yesterday. Set lights up for 2 seconds then goes dark and blinks red light 4 times.

Got the SM and followed flow chart. Have 2.79v on pin 7 of CN6002 on B* board. Next instructions are useless. It's all turned into board swaps. Schematics are rather "general" and offer little specifics.

The methods they want me to follow suggests that I have these boards laying about and that they were free...

Replace power board, if symptoms improve, replace LED driver board, if symptoms improve, replace panel! Really?? WTF!

Can anyone offer some advice on this unit and what I can do to eliminate or check for failure(s)?

T

[tom66]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Is 4 blink an LED/inverter fault?

[Toasty]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Going by the diagnostic chart of codes: 4 times blinking (Balancer Error)

Few possibility: BATV BOARD (which I eliminated with the flow chart**), G* BOARD (power supply), LVDS CABLE.

Doubtful Part: LD BOARD (LED driver), LCD PANEL

**
[Check PANEL_FAIL at pin 7 of CN6002 on the B* Board]
- Below 0.84v = B* BOARD
- Between 0.84V to 2.65V [Change G* Board]

Attaching PDF's in .rar's from ET

T

PS: Someone explain why RAR's can be 19.07 MB but ZIP's are limited to only 1.91 MB...? Plus, why are PDF's limited to 9.54 MB ?

? ? ? ? ?

[Toasty]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Well, can't get the second one to upload. Keep getting Internal Server Error 500...?

It's 16.8 MB, so it should. Maybe a time-out issue?

T

EDIT: Split it into 2 volumes to try. Let's see...

CARP! Grrrrr! Screws the file name if too long... 4th attempt

.

SUCCESS!! Somebody hand me a First Aid kit...

.

[Topcat]

Re: Sony Bravia KDL-46EX723 - 4 blink code

I increased the sizes............

[Toasty]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Thank You, Oh Grand PooBah!

[budm]

Re: Sony Bravia KDL-46EX723 - 4 blink code

See https://www.badcaps.net/forum/showth...t=25810&page=2 post39 download 'CTV-45 EX1 DIRECT LCD.pdf' training manual, see page 44~45to help explain the BALANCER ERROR. It may not have the same pinout but still the same function.

[Toasty]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Thanks Tom & Bud.

This is an LED TV. I'm assuming from what I read that there's a bad LED strip, and they say to replace the panel.

Is there a source for these lamps as there is for CCFL's?

T

[freakaftr8]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Is this set edgelit or backlit? Either way the leds are usually in strips anyhow. Theeenis another member here going through the same issue or similar to whats going on with yours. Can you see any dark areas of the panel the few seconds its lit?

[Toasty]

Re: Sony Bravia KDL-46EX723 - 4 blink code

KDL-46EX723 is Edge LED.

See: Technical Specs for KDL-46EX723

I'll have to do this in a dark room as it's dark grey when on and there is some OSD.

T

[freakaftr8]

Re: Sony Bravia KDL-46EX723 - 4 blink code

OSD huh. it seems to eliminate tcon B board voltages and power supply is far is displaying goes. Time to spec out voltage on the balancr ics. Are there six of them?

[Toasty]

Re: Sony Bravia KDL-46EX723 - 4 blink code

No IC's. I think 4 MOSFETs on the LED driver board which then feeds through the LVDS board.

Dark room testing with remote allowed me to quickly switch inputs. The display looks "normal" and bright when I get to TV antenna input and "snow". I have only a few seconds, but have managed to switch through them. All the other inputs seem to illuminate the screen evenly.

If I turn the set off quickly, it never gets to blink, just standby. I can then power it on again and switch again. If I don't switch it off quick enough, it goes to blinking and I have to unplug it and start again.

T

[tom66]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Is there an ERROR output on the LED board? If so, try checking that before & after failure. If there is such an output you can probably pull it low with a 100 ohm resistor then toggle the BL ON/OFF line to your liking to use the backlight temporarily without having to power cycle the TV.

[tibimakai]

Re: Sony Bravia KDL-46EX723 - 4 blink code

I have the same error on a 46NX720 and it seems that the LED driver board is at fault.
On mine there are six driver ICs and they all have a Fail test point next to them. 5 of them showed 0.589V and one of them, 0.3xxV.
I'm guessing if the driver ICs were all OK, then those fail test points would show the same voltage and then the LED strips would be the problem.
All the LEDs turn on and some of them will dim and then the TV will turn off.
I have ordered the board from shopjimmy and waiting now to arrive.

[freakaftr8]

Re: Sony Bravia KDL-46EX723 - 4 blink code

I have the same error on a 46NX720 and it seems that the LED driver board is at fault.
On mine there are six driver ICs and they all have a Fail test point next to them. 5 of them showed 0.589V and one of them, 0.3xxV.
I'm guessing if the driver ICs were all OK, then those fail test points would show the same voltage and then the LED strips would be the problem.
All the LEDs turn on and some of them will dim and then the TV will turn off.
I have ordered the board from shopjimmy and waiting now to arrive.

Your the one I was thinking about when the op posted this thread.

Is it just me or does it seem like just a slight possibility here that these new led TVs gave a very limited window for led wear? I mean with LCD TVs with CCFL backlight they seem to go on and on and on until the one of the backlight ccfl's fail. These TVs seem to have no room for led wear when they start to differ on balance they automatically send a code and won't work anymore.

[Toasty]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Curiosity - Why would you order the board? What led you to believe the board is at fault and not one of the LED strips?

I did check somewhat further and found that all 4 of the outputs from the LED driver board at initial power on are reading 140v. This matches the voltage produced by the power board (G5D in my case), which remains at that level after shutdown.

There is a 40 pin driver IC for the 4 LED circuits that has a FAIL output which triggers a LD_ERR line that goes back to the PSU. I presume that when the IC senses a problem with the LED's, it signals the shutdown. I will measure across the driver circuits tomorrow to see if I can determine which one(s) is/are the issue.

IMO at this point, I think there is a failure of some of the LED's in the panel. Voltages on the PSU all look solid and the output seems to be correct across the 4 drivers.

T

[freakaftr8]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Well pull the panel and see. If none are bad you could provide a low to the fail pin to trick the B board to allow leds to come up

[tibimakai]

Re: Sony Bravia KDL-46EX723 - 4 blink code

I have switched the ribbon cables between them (in pairs, not in X) and the dimming followed.

[Toasty]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Ok, gotcha.

Mine does not have that ability. No ribbons to switch, just 2 connectors. A 4 pin for common V+ (140v) and a 5 pin (with 4 used) for output from the driver MOSFETs.

Taking the panel apart will be a last step. I don't like doing it until I can prove that it's the problem.

I see some strips available for this panel (LTY460HJ05-003).

@freakaftr8 - re: LED wear - Yeah, they should be like Christmas light strings... When one goes out the rest stay lit...

T

[freakaftr8]

Re: Sony Bravia KDL-46EX723 - 4 blink code

Yes and thus changing current and amp loads.