Toshibia 40rv525u Blinking Power light

[knoxrebel]

Was given this tv It was missing the power board, but i had the original part number. I installed the new board and the power light blinks but no picture.

There is a click heard on the power board that is the same rate as the flash of the power light.

I tested power coming out of the power board to the power switch/video board. Standyby 5v is good when no other boards are connected, but as soon as the video board/power button is connected the voltages pulse with the clicking and blinking of the lights.
Filter Caps measure 170 across both.




Sorry I don't have a camera today, if needed these pictures are the same as what i have.
https://www.badcaps.net/forum/showth...light=40rv525u

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Tested:
u13-
Pin 1 12v drops to 2.5
pin 2 8v drops to 2.5

u14-
Pin 1 9v drops to 2
pin 2 5v drops to .5

u7-
1 - 0v
2 - 1.6 drops to 0
3 - 3v drops to 0

[tom66]

Re: Toshibia 40rv525u Blinking Power light

[Ignore this - I was being silly.] It's not a Vestel chassis. Is it a European or US model?

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Us

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Here are the pics of my boards. Wish they would bump up the size of the images allowed.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Bump

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Does this appear to be symptoms of a bad power board or an issue with the video board not allowing the unit to fully power on?

EDIT: Shorted pwr pin to 5v standby. Tested all output voltages from power board and all voltages look good.

[Rtech]

Re: Toshibia 40rv525u Blinking Power light

|have you tried it with the Inverter disconnected ???

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Yes, I tried without the inverter.

[budm]

Re: Toshibia 40rv525u Blinking Power light

Can I see the closed up pictures of the connectors on the power supply board so I can see the function of the pins then I may be able to tell you how to do stand alone testing of the power supply board.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Here they are.

[budm]

Re: Toshibia 40rv525u Blinking Power light

Can you read DC voltage for me at P8 pin 4 (PWR) and the chassis when the TV is plugged in but not turn on, and when power switch is activated? Same for PIN 1 (INV).

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

The pwr pin to ground goes up to 4.5v then to 0 repeatedly. Pin 1 (inv) to ground i get .5 peak then 0 repeatedly. No change when the power button is pressed. The power board is making a sound like it is coming on, the voltage peaks then drops and repeats.

[budm]

Re: Toshibia 40rv525u Blinking Power light

OK, it seems like the PWR on signal is toggling on and off. Put your meter on the 5V Pin and read the voltage when TV is OFF and when TV is on, I want to know what this 5V for the main board is doing steady.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

5v goes down to ~1.5 when the unit tries to power on. Power button has no effect.

[budm]

Re: Toshibia 40rv525u Blinking Power light

That 5V should be at 5V at all, it is always on the minute you plug the TV into the outlet. I still need to know if 5V is there BEFORE you hit the power switch, what I am trying to find out is: The main board is loading down the power supply, or the power supply just cannot supply enough power to run the board. This is the replacement you bought?
You can also disconnect the connector to the main board and put 10 Ohms 5watts to load the 5V output for about 1/2A to see if it can handle that.
You can also try replacing the caps in red circles for the 5V power supply section.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

The 5v is steady with no other boards plugged in. With the other boards plugged in the 5v is present as soon as the tv is plugged in, but immediately starts fluctuating. (not pressing pwr button)

[budm]

Re: Toshibia 40rv525u Blinking Power light

Try new caps first. This 5V is always running 24/7 the minute the TV is plugged into the outlet, that is why it is called standby or always on power supply. It can fail after all these years being left plugged in 24/7.
Did you also try loading the 5V line with the resistor? We want to make sure you do not have short circuits in your main board that is loading down this 5V power supply.

[tom66]

Re: Toshibia 40rv525u Blinking Power light

Those are very good Rubycon caps. Why are you replacing them? They hardly ever fail.

[budm]

Re: Toshibia 40rv525u Blinking Power light

Well I see lots of bad Rubycon caps from my experience also.
Even MAC computers failed due to bad Rybycon caps.