SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green light

[sacrh]

SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green light

We came one evening & realized this problem when tried to turn on the TV (SONY KDL-52ex700), there has been, no sound, no picture, no click sound (for backlight).
Here is the sequence I have checked so far.
1. Pressing the Energy saving switch button, TV used to turn ON green light, get backlight click sound & used to show Sony logo with sound
- None above happen anymore. No green light, No sound, no picture, No backlight
2. Pressing the power switch button used to either put the TV in standby mode OR turn on green light, get backlight click sound & used to show Sony logo with sound
- Now when pressed first time I can do get Red stand by light & after pressing one more time gets green light but then no sound or logo
3. Checked for few minutes, on Green light & it remains solid green & does not turn Red until I press remote button to Standby mode. So Red light do not blink. Remains solid Red.
4. Backlights are not illuminated at any time
4. As per few suggestions changed the main board but all above behavior remains same. Said that I felt "probably" it didn't used to respond to other keys on the remote (like volume, channel change etc). But not very sure (I can replcae the original board & confirm if needed).
5. I checked the voltages & initially felt problem was more likely with logic board, as I do get 3.3V on Stand-by pin on Power board connector as well as Logic board input connector.
6. Gets 3.3V at connector CN6150 (picture attached) but do NOT get voltages on any other pins of the connector, either in Stand-by or Power On mode.

Question is, Do the other pin voltages on CN6150 are triggered thru the main board? Or should they be available all the times once in standby or power ON mode? Should I have replaced the Power board instead of Logic board?
Is there any flow diagram which shows how the voltages exactly flows thru this model of Sony. Unfortunately I didnt find the Schematic Board circuit diagrams for this particular model on any websites.

Will really appreciate any help on this.

Thanks
Sachin

[budm]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

https://www.badcaps.net/forum/showthread.php?t=25810
May be you will understand more as to what the TV requires to operate.
Service manuals:
http://elektrotanya.com/?q=showresul...oria=&kat2=all

Training manuals:
http://elektrotanya.com/?q=showresul...oria=&kat2=all

There are also many thread at BC about this model.

[sacrh]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

After doing some more diagnosis felt the Power board seems to be the issue somwehere. As the green light turns on I will be curious to know how the voltages flow. Where can I verify the voltages flow between different boards. Specifically triggering of high voltages on Power board from logic board. Went thru dufferent manuals but will appreciate any inputs or do we have any thread running on that?

[attainteddragon]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

if you want more help, you need to upload some pics of the entire rear of the set and a pic of each board.

we assume that you have a dmm and basic usage knowledge to proceed further.

[budm]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

After doing some more diagnosis felt the Power board seems to be the issue somwehere. As the green light turns on I will be curious to know how the voltages flow. Where can I verify the voltages flow between different boards. Specifically triggering of high voltages on Power board from logic board. Went thru dufferent manuals but will appreciate any inputs or do we have any thread running on that?

You need top look at the diagram of each board and then look at your TV to see how the wire harness are connected between each board, the connectors of the boards have pin name and pin number to tell you what they are. You know how to read schematic, right?

[sacrh]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

You need top look at the diagram of each board and then look at your TV to see how the wire harness are connected between each board, the connectors of the boards have pin name and pin number to tell you what they are. You know how to read schematic, right?

My apologies for the delayed response.
Yes very well aware of the schematics & have all the gears at home. DMM, Soldering kit, etc..

I have attached pictures of the back of the TV, Power board & Main/Logic board (replaced this day back so not original). Also atached some schemtics diagram from the manual.

Thanks

[budm]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

You have the schematic of the power supply that you can see the connector pin names to tell you what they are.

[sacrh]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

You have the schematic of the power supply that you can see the connector pin names to tell you what they are.

Was curious if there is any document/picture shows the flow of voltage. Meanwhile I changed the Power board & Main board & almost able to had everything working. Sony logo comes up with the sound. Was able to upgrade the firmware, set the network configuration & tune & watch the channels. The problme I am running into now is, after around 10-15 mins watching, the TV turns off & then gives "6" blinks of the Red standby light.

The diagnostic manuals for 6 Red light blinks says,
6 BACKLITE_ Back Light Error (Panel Inverter)

Not sure what exactly that means but as I have alreayd changed Power & Main board. So is this T-Coon board issue? After going thru manuals, my understanding of this error & Panel board so far is not clear.

Any advice?

Thanks

[budm]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

BACKLIGHTS issue.
"Was curious if there is any document/picture shows the flow of voltage." What does that mean the 'The flow of the Voltage'?
Turn down the backlights level (not brightness) to see if the backlights will stay on longer.

[sacrh]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

BACKLIGHTS issue.
"Was curious if there is any document/picture shows the flow of voltage." What does that mean the 'The flow of the Voltage'?
Turn down the backlights level (not brightness) to see if the backlights will stay on longer.

By 'Flow of voltage', I was referring to functional flow, once Power Switch is turned ON, & then from standby mode untill there is a picture on the screen. Possible voltages on various connector pins & IC's during this process. Like when TV is in standby & then in power ON mode. Basically which pin I should get how much voltage at what point of time (mainly I was curious about pins on connector 6150 on power board) & different pins on IC's on Main board. Also how the high voltages are triggered on Power board from main board. What are the voltages expected across different connector pins during the process.

For example I realized my original power board wasnt showing any voltage across all pins on 6150 except 3.3v on Pin1 & it remained that way even after Power ON (green light was ON). The board circuit digram mention the details in limt.

Meanwhile I will change the backlights level from picture setup & update in few hours.

Thank you

[sacrh]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

I turned down the backlights level (from middle to low) & now the TV turns off within 10-15 seconds .. I do not even get chance to revert that settings. By the time I can reach the picture setting the TV is turned off.

[sacrh]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

Any thoughts. Which one is thepanel board?

[budm]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

So did you download this service manual?
sony_kdl-32ex700_40ex_46ex_52ex_60ex700_701_703_chassis_az1-l_9-888-268-51_ver.1.0.pdf
Did you look at page 34 where CN6150 is and see all those pin label to tell you what they are?
In post 1 you said you do not have backlights but now you do which means that there is no way you can have all 0V readings on all the pin except the 3.3V pin. BTW, did you read the basic training so you will understand what the PS-ON and BL-ON are for?
At this point since you do have backlights on at least 10~15 seconds, then what you need to do is to put black probe of the DC meter on the chassis, put the red probe on pin 1 (or pin 2, these are the Anode pin of the LED strings) of the LED connector CN6800 then turn on the TV and see how high the Voltage goes up to before it goes out, record that reading. Turn the TV off then move the red probe to CN6801 pin1 (Cathode return of LED string 1) then turn on the TV and see how high the Voltage goes up to before the backlights go black then turn off the TV. Put red probe on the CN6801 PIN 2 (Cathode return of LED string 2) then turn on the TV and see how high the Voltage goes up to before the backlights go black then turn off the TV. Report all those readings.
BTW you look at page 34 of the schematic then you see how the LED strings are driven. BTW, how much electronics knowlegde do you have? For example: do you know how the Transistor is turned on and off? If you want me to help to do in-depth trouble shooting I will need to know how much you know first.
For example the connector CN6150 pin 3 (Power _on), if you follow that connection you will see where it goes to which if you understand the circuit then you hsould know that pin 3 is the signal Receiving pin and you can see how high the Voltage on that pin should be to turn on the Transistor.

[budm]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

http://www.shopjimmy.com/sony-1-474-...wer-board.htm#
Sony 1-474-212-11 (APS-263(CH), 1-881-773-12) GE2 Power Board

[sacrh]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

So did you download this service manual?
sony_kdl-32ex700_40ex_46ex_52ex_60ex700_701_703_chassis_az1-l_9-888-268-51_ver.1.0.pdf
Did you look at page 34 where CN6150 is and see all those pin label to tell you what they are?
In post 1 you said you do not have backlights but now you do which means that there is no way you can have all 0V readings on all the pin except the 3.3V pin. BTW, did you read the basic training so you will understand what the PS-ON and BL-ON are for?
At this point since you do have backlights on at least 10~15 seconds, then what you need to do is to put black probe of the DC meter on the chassis, put the red probe on pin 1 (or pin 2, these are the Anode pin of the LED strings) of the LED connector CN6800 then turn on the TV and see how high the Voltage goes up to before it goes out, record that reading. Turn the TV off then move the red probe to CN6801 pin1 (Cathode return of LED string 1) then turn on the TV and see how high the Voltage goes up to before the backlights go black then turn off the TV. Put red probe on the CN6801 PIN 2 (Cathode return of LED string 2) then turn on the TV and see how high the Voltage goes up to before the backlights go black then turn off the TV. Report all those readings.
BTW you look at page 34 of the schematic then you see how the LED strings are driven. BTW, how much electronics knowlegde do you have? For example: do you know how the Transistor is turned on and off? If you want me to help to do in-depth trouble shooting I will need to know how much you know first.
For example the connector CN6150 pin 3 (Power _on), if you follow that connection you will see where it goes to which if you understand the circuit then you hsould know that pin 3 is the signal Receiving pin and you can see how high the Voltage on that pin should be to turn on the Transistor.

Budm sir my apologies. I have been working in the office & then busy helping volunteering cleaning work for Hurricane victims around neighborhood since last few weeks. I did spent some time going thru the schematics diagram but was not able to lot time reading material. I did my basic electronics during engineering so very well aware of the diodes capacitors, transistors. Will check few more things for Transistors as it has been a long time.

Really appreciate all the suggestions. Page 34 does make lot of sense as I reviewed it again. I will check the details on all the pins as per your suggestion tomorrow morning & update with the readings details, in table here.

Meanwhile I will be curious to know, why the TV turns off quickly now, after I infact lowered backlight settings from TV menu. It was ON for minimum 10-15 minutes before I lowered that setting. Also I would like to mention that I have replaced both power board & logic board replaced. Can they be faulty also?

Will update the readings soon as per your suggestions.
Thanks Budm

[budm]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

More likely the LEDs are failing and with less current flowing through them when the backlights level is turned down they cannot stay on so it goes into protection shut down. It will be good to have LED tester because opening up the panel is the last thing you will want to do. You can look on EBAY for similar product too.
http://www.shopjimmy.com/sid-gj2c-le...ght-tester.htm

[JoeC39]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

I am having similar problem as SACRH. My SONY KDL46EX700 TV has the standby light blinking 6 times. I downloaded the service manual and went through the troubleshooting check list. It directs me to check JL2565 on the BAL board. If over 2.65V Change G* board. Problem is JL2565 is not identified on the BAL board.

As with SACRH when I power on I get the green light and the usual audible sound when the TV comes on then in a couple seconds it goes off again and the red error light starts blinking 6 times.

When I measured the standby voltage for the specified 3.5V it actually read double at 6.6V. Disconnecting connector CN6150 and testing for 3.5V again it read 6.6V again.

I am assuming that the GE2 power board is bad. Will replace and check again.

[Davi.p]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

before cahnging the PSU have you tested voltage of a known good battery? Maybe tester is bad or low batt.
6 blinks stands for backlight problem, you much probably have a bad led.

[budm]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

6.6V on the 3.3V standby output sounds like measurement error.

[sacrh]

Re: SONY KDL-52ex700: No picture, No sound, No backlight but gets Standby & Green lig

After long I started having the problem (since few months now). But has been more prominent now. Basically whenever the background picture gets dark in the movie or news (night scene etc...), voltage starts dropping & TV turns off. Seems it can not maintain lower voltage requirements of the TV set. Is this the problem with the power supply board? As that's the only board I never replaced? Or is it LED backlight issue?

Appreciate your responses.