⚠ help ⚠ // toshiba 55zv650u

[dan_]

Re: ⚠ help ⚠ // toshiba 55zv650u

Ooo, I get it ~ sorry, that took me a while. It looks like I'm getting close to 0 V at all of those pins.

Adding onto this, I tried measuring the voltage at those pins w/ the main-board connected and also got 0 V. It looks like you found the problem! Any clue how to fix it?

[dick_barton]

Re: ⚠ help ⚠ // toshiba 55zv650u

Now try the same test but this time with the resistor connected between POW_ON and Ground

The normal test for a power supply is to try and get the power supply to run when disconnected from the mainboard.

There is an input; POW_ON in this case, whose voltage is changed when the set is taken out of standby by the mainboard.

Some power supplies will have 3V or more at POW_ON pin that will be go to 0V when taken out of standby and some work in the reverse.

This test is to see if the secondary supplies are working. In this case the 18V, 12V supplies. If all the voltages come up to their value when this test is carried out then this would point to a mainboard fault. If the secondary supplies do not come up to value then this would indicate a power supply fault.

[dan_]

Re: ⚠ help ⚠ // toshiba 55zv650u

Now try the same test but this time with the resistor connected between POW_ON and Ground

The normal test for a power supply is to try and get the power supply to run when disconnected from the mainboard.

There is an input; POW_ON in this case, whose voltage is changed when the set is taken out of standby by the mainboard.

Some power supplies will have 3V or more at POW_ON pin that will be go to 0V when taken out of standby and some work in the reverse.

This test is to see if the secondary supplies are working. In this case the 18V, 12V supplies. If all the voltages come up to their value when this test is carried out then this would point to a mainboard fault. If the secondary supplies do not come up to value then this would indicate a power supply fault.

Thank you for the detailed explanation. I re-connected the resistor between GND & Pow_TV and still got 0 V from probing the 12 V and 18 V pins. Also, one thing I think is worth mentioning, I don't hear the ticking sound when I connect Pow_TV and GND by a resistor and power it up ~ only when connecting the resistor between Pow_TV and 5V1.

[dick_barton]

Re: ⚠ help ⚠ // toshiba 55zv650u

It sounds very much like the out of standby condition is met when POW_ON goes to 5V. As you say, you can then hear a response from the power supply but still have no secondary voltages.
It looks at this point that you have a faulty power supply. Without a schematic it would be difficult to track down the exact fault.

[dan_]

Re: ⚠ help ⚠ // toshiba 55zv650u

It sounds very much like the out of standby condition is met when POW_ON goes to 5V. As you say, you can then hear a response from the power supply but still have no secondary voltages.
It looks at this point that you have a faulty power supply. Without a schematic it would be difficult to track down the exact fault.

I'm guessing these schematics are not available to the public?

[budm]

Re: ⚠ help ⚠ // toshiba 55zv650u

To be clear, all 3 red round fuses are OK, correct?
Did you read this thread? https://www.badcaps.net/forum/showthread.php?t=56173
And also search for power supply PE0702A threads.

[dan_]

Re: ⚠ help ⚠ // toshiba 55zv650u

To be clear, all 3 red round fuses are OK, correct?
Did you read this thread? https://www.badcaps.net/forum/showthread.php?t=56173
And also search for power supply PE0702A threads.

Hey, @budm!

Thank you for the message but... I've got bad news.

I went on to test the fuses and they were alright. Next, I moved on to reading the post you sent and saw that the FETs could be the problem. Using a video as reference (https://www.youtube.com/watch?v=RkWy1EirEu8), I went on to test them until...

I saw a spark on the R850 ceramic resistor and... Just like that, it was burnt. I replaced it but, when plugging in the TV I no longer hear the relay engage (w/ the tick) and I'm getting the wrong AC and DC voltages across the bridge rectifier ~ which tells me that the voltage regulator might be dead too.

Sooo... At this point, I'm not sure if it is still worth it to continue :/