Toshibia 40rv525u Green Blinking light and questions about Caps!!

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Okay using the resistor to pull the pwr pin up to the +5v rail. I was getting a measurement that fluctuated between 0.16 then went up to 0.58 so there is no question that there is a problem with the standby part of the psu.

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Okay using the resistor to pull the pwr pin up to the +5v rail. I was getting a measurement that fluctuated between 0.16 then went up to 0.58 so there is no question that there is a problem with the standby part of the psu.

Yes; either that or the pre-charge for the primary (it depends on the topology.)

I've got to go now, but I'll post another test soon.

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Okay, let's try and make future tests easier:

Unplug all power to TV, let it sit for a couple of minutes.

Check the voltage across each big capacitor. Does it drop to nearly zero? This is for safety reasons. I want to know if it is safe for you to handle the board after it has been sitting for a couple of minutes.

Now, we need to find the common ground for the primary. I suspect it will be the negative lead of the capacitor closest to the AC input, but I'm not certain. So, with the board still switched off, check the resistance from each lead of each capacitor on the 200 ohm range to pin 10. One should give nearly zero ohms.

Oh, and double check you are definitely probing the pins I've highlighted which are 10 and 12 and not some other strange pins. Don't worry, I've done it too many times before :/.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Hey, Thanks! Glad to see were getting somewhere in the testing.

1. Yes the voltage across each big capacitor drains to about 5 volts in around a minute. And after a while the 5 volts drains too.

2. Using the pin with the black arrow pin 10 I tested to the different Pins of the caps and found that the pin of C120 circled in the picture read 0.5ohms but touching my probes read about the same so it is basically 0ohms. Also that pin of the Cap is connected to ground by CY103 as you can see in the picture, which I believe is a cap.

Also I probed pin 12 and noticed that it was also connected to the pin of C120 circled in the picture and that it read 5.5 ohms or around 5ohms with the probes taken out does this indicate a short?


3. Double Checked that it was pins 10 and 12 still got a reading the was unstable going from 0.16 to 0.57 or so.

Okay, check the voltage between these two pins with PSON both high and low using the resistor.

You should get around 9 to 16V if it is working okay, typically when PSON is high. When PSON is low, it might drop below 9V. If the voltage here isn't high enough, it points to a problem in the pre-charge or the standby power part.

Also if I understood right you just wanted me to pull up the PWR pin with the resistor attached to the +5v rail is that correct?

Thanks!

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Also I probed pin 12 and noticed that it was also connected to the pin of C120 circled in the picture and that it read 5.5 ohms or around 5ohms with the probes taken out does this indicate a short?

Yes; that seems to indicate something is not right. Check the ohms resistance on the 200 ohm range between 10 and 12, if that shows up as about 5 ohms then it's probably failed. It's a fairly common failure with power supplies.

Looks like the part is $4 on eBay: http://www.ebay.com/itm/L6599D-L6599...item415e5ae292

or from DigiKey: http://search.digikey.com/us/en/prod...9-1-ND/2021190 + ~$3 shipping in USA. This part will arrive quicker.

You will also need solder wick to remove the original and a steady hand to replace it. It might be a good idea to use a bit of glue to secure the new chip down whilst you try to solder it.

Also if I understood right you just wanted me to pull up the PWR pin with the resistor attached to the +5v rail is that correct?

Thanks!

Yep. 5V standby.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

OK it 5.5ohms across the pins. Would this just fry by itself?

Should I get more than one In case the new one frys, too? How can I tell if there isn't another problem?

Also, what other components would you hold suspect? Since its cheaper to buy and have them all shipped in one shot what would you get?

Thanks!

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Oh and what size and type solder wick should I get?

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

OK it 5.5ohms across the pins. Would this just fry by itself?

They do seem to do that. I'm guessing a mains surge might be responsible, or if they are operated for a long time near their limits. Or sometimes there can be a defective chip off the factory line.

Should I get more than one In case the new one frys, too? How can I tell if there isn't another problem?

That would be a good idea.

Also, what other components would you hold suspect? Since its cheaper to buy and have them all shipped in one shot what would you get?

Thanks!

I don't think anything else at the moment is up. That short is a clue.

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Oh and what size and type solder wick should I get?

1.5mm is fine, make sure it has flux added. (Solder wick without flux is essentially copper wire and is useless for desoldering.)

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Is this right?

http://media.digikey.com/Photos/Multicore/M293366.jpg

Or do i get one with rosin?

http://search.digikey.com/us/en/prod...1087-ND/350542

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

They do seem to do that. I'm guessing a mains surge might be responsible, or if they are operated for a long time near their limits. Or sometimes there can be a defective chip off the factory line.



That would be a good idea.



I don't think anything else at the moment is up. That short is a clue.

Ok if I pull the chip and the pads on the board still read 5.5 ohms does that mean there is a short on the board instead?

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Ok if I pull the chip and the pads on the board still read 5.5 ohms does that mean there is a short on the board instead?

Yes, most likely. But the only path to ground is through that chip; unless Toshiba (or more likely, FSP, the people who designed it) have used a different circuit design.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

For desoldering wick Is this right?

http://media.digikey.com/Photos/Multicore/M293366.jpg

Or do i get one with rosin?

http://search.digikey.com/us/en/prod...1087-ND/350542

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

First one is fine, second one is not found?

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

I don't know what happened there,

http://search.digikey.com/us/en/prod...148-ND/2498946

w/rosin

http://search.digikey.com/us/en/prod...1087-ND/350542

I take that no clean has flux, since they have unfluxed?

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

The Multicore stuff is all you need.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Good news! I pulled the chip and its measuring 5.5 ohms without being in the curcuit. The board reads out of range. The new one is on order.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

I am getting my list together.

I think I am going to replace a couple of the Caps when I have it apart.

What is suggested as a replacement?

I was only going to replace these Caps on the board.

Replacing List

All are Nippon Ky Series 105C Capacitors
One 1000uf 25v
Three 1000uf 35v
Two 100uf 25v caps.
One 10uf 50v
One 22uf 50v
One 47uf 25v

Leaving List

All Film/Mylar Caps
All Ceramic Caps
The Two Main Filter Caps
The two 1500uf 10v YXG Series 105C Rubycon's


Is that OK should I order any of the other ones?

Also, I was just going to combine the 1000uf 25v
and 1000uf 35v Caps and just get a lot of 25 or so of 1000uf 35v Caps is that ok?

What is suggested as a replacement, should I get the same Series and Brand? I would like to try to get them all at Digi-Key, and the smaller Ky Series caps aren't in stock right now and i don't feel like waiting. Thanks!

Thanks!

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

There is really no need to replace the caps as the originals are very high quality United Chemi-Con and Rubycon - probably the two best capacitor manufacturers in the world. Don't fix something that's not broken . Toshiba obviously spent a few pennies extra to make the TV last longer, same for another Toshiba I have.

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Just remember when replacing the chip to make a note of which way around it goes - the little black detents should match up.