Sony KDL-460EX500 Totally Dead - With Standby

[jason123]

Hi
I received a Sony KDL-46EX500 that I'm not sure where to start on.

No lights (standby- red or Green)

3.3 V is present on STBY (3.248V)
AC-OFF-DET is 2.79 V
POWER-ON is 3.23 V
BL-ERR is 3.2 V

All other voltages on the Power and main board are in the 0V range

The POWER-ON Does not change when the keypad button is pushed (main board), yet the actual power key signal on the main board is triggering (Goes to 0 V when keypad power button is pushed, and returns to 3.xxV when not pressed)

The Manual indicates that I have to replace the GD2 (Power) board. though the power button behavior makes me suspect that in addition, the Main board is dead?

I don't want to spend money to replace bother boards as the TV is not worth the costs of individual boards. Just wanted to check my theory that both boards are dead (maybe even the Inverter since the BL-ERR signal is 3.3 V)

I found a kit on eBay and ShopJimmy, but the fine print states that R6536 would be open in this failure mode that the kit would fix. My R6536 on the GD2 is reading 23.3kOhm.

[nomoresonys]

Re: Sony KDL-460EX500 Totally Dead - With Standby

What happens when you unplug mainboard from powerboard and turn on tv?

[budm]

Re: Sony KDL-460EX500 Totally Dead - With Standby

Hi
I received a Sony KDL-46EX500 that I'm not sure where to start on.

No lights (standby- red or Green)

3.3 V is present on STBY (3.248V)
AC-OFF-DET is 2.79 V
POWER-ON is 3.23 V
BL-ERR is 3.2 V

All other voltages on the Power and main board are in the 0V range

The POWER-ON Does not change when the keypad button is pushed (main board), yet the actual power key signal on the main board is triggering (Goes to 0 V when keypad power button is pushed, and returns to 3.xxV when not pressed)

The Manual indicates that I have to replace the GD2 (Power) board. though the power button behavior makes me suspect that in addition, the Main board is dead?

I don't want to spend money to replace bother boards as the TV is not worth the costs of individual boards. Just wanted to check my theory that both boards are dead (maybe even the Inverter since the BL-ERR signal is 3.3 V)

I found a kit on eBay and ShopJimmy, but the fine print states that R6536 would be open in this failure mode that the kit would fix. My R6536 on the GD2 is reading 23.3kOhm.

Look at the resistance of the R6536 as printed on the body of the resistor then you will know why your R6536 is no good, the GD2 board may have some shorted out component that takes out R6536.

[jason123]

Re: Sony KDL-460EX500 Totally Dead - With Standby

What happens when you unplug mainboard from powerboard and turn on tv?

Just tried. Nothing at all. Just the click when I connect the AC cable (relay) and that's it.

[jason123]

Re: Sony KDL-460EX500 Totally Dead - With Standby

Look at the resistance of the R6536 as printed on the body of the resistor then you will know why your R6536 is no good, the GD2 board may have some shorted out component that takes out R6536.

the photo I provided is one I stole from another post here. My board is identical but my resistor has "U40" on it, that's all. Can't tell what value that is. Any thoughts?

[budwich]

Re: Sony KDL-460EX500 Totally Dead - With Standby

you might want to do a "nice list" of the labels versus measurement of the connectors of ALL the pins at the power supply at power plugged in and then again at power on button pushed. NOTE: you might have to watch some of those pins "quickly" at they may change "state" rapidly. It would appear from your first "description" you are missing 12v everywhere.... or could be your oversight. :-)

[jason123]

Re: Sony KDL-460EX500 Totally Dead - With Standby

you might want to do a "nice list" of the labels versus measurement of the connectors of ALL the pins at the power supply at power plugged in and then again at power on button pushed. NOTE: you might have to watch some of those pins "quickly" at they may change "state" rapidly. It would appear from your first "description" you are missing 12v everywhere.... or could be your oversight. :-)

Thanks. The short list of voltages are everything that I could measure on the PS board. All the rest are 0 (+/- few mV)

STBY 3.3 V is present as 3.248V
AC-OFF-DET is 2.79 V
POWER-ON is 3.23 V
BL-ERR is 3.2 V

All other pins on the board are 0 V

[nomoresonys]

Re: Sony KDL-460EX500 Totally Dead - With Standby

Maybe test powerboard with mainboard unplugged, using resistor/s, see if your other voltages come back.

[nomoresonys]

Re: Sony KDL-460EX500 Totally Dead - With Standby

Could try with everthing hooked up, heating powerboard with hairdryer small section at a time, see if tv tries to come on or if anything changes, heat the startup caps, optocouplers and the usual suspects.

[budwich]

Re: Sony KDL-460EX500 Totally Dead - With Standby

Thanks. The short list of voltages are everything that I could measure on the PS board. All the rest are 0 (+/- few mV)

STBY 3.3 V is present as 3.248V
AC-OFF-DET is 2.79 V
POWER-ON is 3.23 V
BL-ERR is 3.2 V

All other pins on the board are 0 V

OK... so you were watching 12v reg while you pressed power on to see if it ever changes?

IF it never does anything, then that should be where your focus is... tracing the 12v in the power supply circuit toward some regulator to see if that regulator is "good" and has got what is needed to do its regulation.

Of course, having a BL-ER is not likely to help anything... since that I believe that is sent to the main board. Bad inverter / tube?

Probably since the inverter likely has NO 12v going to it either, its "logic" can't help but set the bl-er... maybe.

[budm]

Re: Sony KDL-460EX500 Totally Dead - With Standby

the photo I provided is one I stole from another post here. My board is identical but my resistor has "U40" on it, that's all. Can't tell what value that is. Any thoughts?

https://www.badcaps.net/forum/attach...5&d=1556131901
1) So this is not the picture of your board?
2) Show us the pictures of YOUR board and the pictures of the fusible resistor R6536, there should be lots of printing on that body of that resistor R6536. It should be 0.47 Ohms fusible resistor as printed on the body.
3) If that fusible resistor has gone open circuit then there will be no 12V, no high Voltage from the inverter section.

Is this your board with matching numbers? I do not see U40 printed on the resistor.

Shopjimmy:
https://www.shopjimmy.com/sony-1-474...er-supply.htm#

[jason123]

Re: Sony KDL-460EX500 Totally Dead - With Standby

OK... so you were watching 12v reg while you pressed power on to see if it ever changes?

IF it never does anything, then that should be where your focus is... tracing the 12v in the power supply circuit toward some regulator to see if that regulator is "good" and has got what is needed to do its regulation.

Of course, having a BL-ER is not likely to help anything... since that I believe that is sent to the main board. Bad inverter / tube?

I was looking at the POWER-ON pin on the PS board. That one is steady 3.23 V regardless of pressed or not pressed keypad power button. Since the PS is not seeing a change on that pin, I'd think the REG12V pins would not change - and that's the case - Just verified. Yes, the 12V seems to dead everywhere.

I need to find out the correct value for the R6536. budm seems to imply that the value of 23.3k is out of spec, and I'm asking around for that value. If indeed it's off, then I'll get the repair kit for $16.xx from ShopJimmy and will attempt a board repair.

[budm]

Re: Sony KDL-460EX500 Totally Dead - With Standby

I was looking at the POWER-ON pin on the PS board. That one is steady 3.23 V regardless of pressed or not pressed keypad power button. Since the PS is not seeing a change on that pin, I'd think the REG12V pins would not change - and that's the case - Just verified. Yes, the 12V seems to dead everywhere.

I need to find out the correct value for the R6536. budm seems to imply that the value of 23.3k is out of spec, and I'm asking around for that value. If indeed it's off, then I'll get the repair kit for $16.xx from ShopJimmy and will attempt a board repair.

If actually look at R6536, you will see the value printed right on that body of the resistor if we are looking at the correct board. read post #11.

[jason123]

Re: Sony KDL-460EX500 Totally Dead - With Standby

https://www.badcaps.net/forum/attach...5&d=1556131901
1) So this is not the picture of your board?
2) Show us the pictures of YOUR board and the pictures of the fusible resistor R6536, there should be lots of printing on that body of that resistor R6536.
3) If that fusible resistor has gone open circuit then there will be no 12V, no high Voltage from the inverter section.

Is this your board with matching numbers?
Shopjimmy:
https://www.shopjimmy.com/sony-1-474...er-supply.htm#

1) No this is not a picture of my boards - I found them on another post here - They're the same part layout and numbers and TV model, but not my actual TV.
2) Attached is my board - I'll get a better photo. U40 is the only thing I can see on that resistor.. I'll get one of the kids to look as my eyesight is not what it used to be

3) Fusible resistor value is 23.3k - Kit states that it will work with TVs that have this resistor open. 23.3k is definitely not open. Will the kit still be a good investment?
Thanks

[budm]

Re: Sony KDL-460EX500 Totally Dead - With Standby

1) No this is not a picture of my boards - I found them on another post here - They're the same part layout and numbers and TV model, but not my actual TV.
2) Attached is my board - I'll get a better photo.
3) Fusible resistor value is 23.3k - Kit states that it will work with TVs that have this resistor open. 23.3k is definitely not open. Will the kit still be a good investment?
Thanks

It is open, it shows 23K on meter because it is still connected in the circuit, so take it out and show us what is printed on that white body of the fusible resistor.
You need to test the MOSFETs in the inverter section and in the 12V section to see if any of them shorted out not which will cause the resistor to blow.

[jason123]

Re: Sony KDL-460EX500 Totally Dead - With Standby

Here are photos of the body - Yes, out of circuit, it's reading open.
I ordered the shopjimmy kit.. will update when I get it.

Thank you

P.S., I was thinking the BL-ERR is a signal coming from the PS card and at 3.2xV, I was thinking this is telling the Main board there is an issue with the BL. But, I removed that signal line from the connector to the PS, and the wire is still 3.2V (coming from the Main Board).. how would the mainboard know there is a BL-ERR? Or is it expecting a pull-down on the PS? Anyone with schematics?

[R_J]

Re: Sony KDL-460EX500 Totally Dead - With Standby

R6536 is a a 0.47Ω 1/2 watt RF, if open check for shorted Q6101 & Q6102
BL_ERR has a 10k pullup resistor to D+3.3V on the main board

[jason123]

Re: Sony KDL-460EX500 Totally Dead - With Standby

Both Q6101 and Q6102 are shorted. Hope the kit will catch all blown parts. Thank you

[R_J]

Re: Sony KDL-460EX500 Totally Dead - With Standby

If Q6101/2 are shorted, also check the gate resistors, R6117,R6118 (10Ω), D6103,D6104. The diodes may read strange in circuit because they have a 330Ω in parallel
That kit seems to include a lot of parts you likely don't need to change, one being the standby ic and if Q6601 - Q6604 are good, ic6601 should be ok (backlight circuit)

to be honest I would have just ordered the fets and a new resistor

[jason123]

Re: Sony KDL-460EX500 Totally Dead - With Standby

If Q6101/2 are shorted, also check the gate resistors, R6117,R6118 (10Ω), D6103,D6104. The diodes may read strange in circuit because they have a 330Ω in parallel
That kit seems to include a lot of parts you likely don't need to change, one being the standby ic and if Q6601 - Q6604 are good, ic6601 should be ok (backlight circuit)

to be honest I would have just ordered the fets and a new resistor

Thanks R_J - Everything you mention checks out except the diodes as you guessed. R6111 (next to R6117) reads 13.3 Ohm (labeled as 10k) and R6112 (next to R6118) reads 29.7 (labeled as 10k). These might have another resistor network or read off because the Qs are shorted?