Sony KDL-40EX710 - Lightning strike and power surge

[sat3182000]

Hi All,

I am an electronics enthusiast and this is my second post, I recently received a TV that was struck by lightning.
Model: KDL-40EX710

The TV used to display the error code 7 blinks. The TV was sent to Sony for repairs but they trashed it as it was an obsolete model. Now after getting back the TV from them. The error codes have vanished. The red light comes on the relay clicks and then after 2 seconds it clicks back again.

So I am trying to reverse engineer the power supply board.
I have standby 3.3 V
I am curious about the voltage in AC_OFF_DET. It shows 3.3 Volt but once I put a jumper on STBY3.3V to POWER_ON the AC_OFF_DET goes to 0V

I feel this is not normal, I remember AC_OFF_DET being 2.3 ish to 2.8ish volts. Please help me out.

I am trying to revive this TV.

[dick_barton]

Re: KDL-40EX710 - Lightning srike and power surge

Do you have any pictures of your boards?

[sat3182000]

Re: KDL-40EX710 - Lightning srike and power surge

Thank you for the quick response.
Yes, I managed to get the circuit as well.

Is there any way I could get the circuit of the main board of the same TV?

ftp://helpedia.com/pub/temp/datashee...8-11_[SCH].pdf


upload images

[dskall]

Re: KDL-40EX710 - Lightning srike and power surge

Link does not open and picture not good enough to see much. I would be checking ac input protection components

[dick_barton]

Re: KDL-40EX710 - Lightning srike and power surge

Looking at the schematic AC_Det going to 0V looks OK. Have you connected 3.3V to Power_On using a 1K resistor to see if the other supplies come up ie 12V, 24V

[sat3182000]

Re: KDL-40EX710 - Lightning srike and power surge

Yes Other supply comes up for a second and then the relay clicks back off

[dick_barton]

Re: KDL-40EX710 - Lightning srike and power surge

Found the data sheet for the CXA3809M-T6 and it says that if the AC in is OK then AC_DETOUT output is High so PH6302 input is not turned on so AC_DET output is also high as you first thought.
Check all the components leading in to AC_DETIN.

[sat3182000]

Re: Sony KDL-40EX710 - Lightning strike and power surge

Status update, The relay latches when I put a jumper on STBY3.3V to POWER_ON. All other 12V does power up for a second.

CXA3809M -> AC_DETIN gets a solid 5V
CXA3809M -> AC_DETOUT get a solid 1.1V

[dskall]

Re: Sony KDL-40EX710 - Lightning strike and power surge

Can you post schematic. Link not opening

[sat3182000]

Re: Sony KDL-40EX710 - Lightning strike and power surge

Please find the attachment

[dskall]

Re: Sony KDL-40EX710 - Lightning strike and power surge

Might check or remove vd6001 and vd6002

[sat3182000]

Re: Sony KDL-40EX710 - Lightning strike and power surge

both are fine.. I get all the 12V outputs for a second and then turns off.

I dont understand 001:15E OVP in the schematic Page2. where does it come from?

[dskall]

Re: Sony KDL-40EX710 - Lightning strike and power surge

You forced power board on with main board disconnected and voltages were temporary

[dick_barton]

Re: Sony KDL-40EX710 - Lightning strike and power surge

Status update, The relay latches when I put a jumper on STBY3.3V to POWER_ON. All other 12V does power up for a second.

CXA3809M -> AC_DETIN gets a solid 5V
CXA3809M -> AC_DETOUT get a solid 1.1V

The STB3.3V is connected to AC_DET so will be a maximum of 3.3V. When the opto-isolator PH6302 is switched on it should go to 0V.

[sat3182000]

Re: Sony KDL-40EX710 - Lightning strike and power surge

You forced power board on with main board disconnected and voltages were temporary

Yes.. I have disconnected all other boards. Just working on Powersupply board.

The STB3.3V is connected to AC_DET so will be a maximum of 3.3V. When the opto-isolator PH6302 is switched on it should go to 0V.

I figured it out, I am looking for the reason why the PSU is shutting down main power once I connect a 1K resistor from STBY_3.3V to Power_ON

[sat3182000]

Re: Sony KDL-40EX710 - Lightning strike and power surge

OK, This seems to be interesting.

PH6300 - PIN 1 and 2 = 1.09V - Turned on
PH6302 - PIN 1 and 2 = 1.05V - Turned on
PH6100 - PIN 1 and 2 = 8.7V - Blown out?
PH6201 - PIN 1 and 2 =0.96 V - Turned on

Looks like something is wrong with PH6100 - I was expecting around 1.2 to 1.4 but its 8.7V looks like it must have blown out.

[sat3182000]

Re: Sony KDL-40EX710 - Lightning strike and power surge

The STB3.3V is connected to AC_DET so will be a maximum of 3.3V. When the opto-isolator PH6302 is switched on it should go to 0V.

Thank you!!! I notice that I did not thank you before

[dick_barton]

Re: Sony KDL-40EX710 - Lightning strike and power surge

PH6100 Pins 1-2 should just have standard diode voltage as you mention for the others so I would also consider replacing it.

[sat3182000]

Re: Sony KDL-40EX710 - Lightning strike and power surge

I did replace the component, still the same voltage on pin 1 and 2

I also noticed something, i do not see the link in the board from PIN 1 of 6100 to Pin 4 of IC6800. Am I reading it wrong?

[dick_barton]

Re: Sony KDL-40EX710 - Lightning strike and power surge

What voltage do you have with the meter probes set to DC placed across Pins 1 & 2


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