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

[ComputerGeek]

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

OK, I'll listen and leave the caps on. Thanks!

[ComputerGeek]

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

OK I have a problem,

I have two spots that have become bridged on the board. Pin1 to the Small SmD Cap? next to it. And Pins 4 and 5 Together.

Now For Pin 1 as I don't see any traces around it I believe that a trace ran to the cap under the white material? Also on the Data sheet this pin is tied to "Gnd via a Cap" or something like that. So does my assertion seem right?

https://cdn.badcaps-static.com/pdfs/...d758189067.pdf


And for Pin 4, I see no traces leaving from it on any side so I am asumming that it is tied to pin 5 under the White separator that is no longer there. Also on the data sheet is says "Tie the pin to pin 4 if burst-mode is not used." which would seem to indicate that they can be tied together.

Does all this seems right? Sorry I tried to get the best pictures possible, but it is rather difficult because my camera does not do macro well.

Thanks!

[tom66]

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

Bridges are normal when removing and replacing... Do you have solder wick? This can be used to remove bridges.

[ComputerGeek]

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

That just it I tried to remove the bridges with the wick, and the solder gets very thin but does not disappear. The bridges actually happened when I was cleaning the board with the desoldering wick.

I think that those pins that I mentioned above are connected under the white pin isolator that was there and got scraped off when I was using the desoldering wick.

^^^ Does my logic in the post above check with the data sheet or not? It seems like the solder bridge is on copper that's why I can't remove it.

[tom66]

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

The green colour of the boards is known as soldermask or solder resist. The soldermask is what stops the pads from shorting to each other and it is what allows the PCB to have those individually metal plated areas.

It's generally difficult to remove the solder mask by accident as it's a strong layer. Very high temperatures and sharp objects can break it. Try adding a little solder to the pads. Seems counter-intuitive but it can help remove the existing solder.

If you still can't remove it, get an good sharp knife and cut the pad and track. It's okay to do this as long as you are careful.

[ComputerGeek]

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

Hmm, I already tried more solder. It won't come off.

I had someone else look at it and it seems like both of these pads/components are supposed to be connected. I don't really know how to read datasheets, But would it make sense for pin 4 and 5 to be connected according to the datasheet? Also doesn't pin 1 have to be connected for this chip to function?

[tom66]

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

You may be right about the intentional connection:

Tie the pin to RFmin (pin 4) if burst-mode is not used.

Burst mode is an energy saving mode which might be used if the TV used the same chip for both standby and main power, but it doesn't. So it would make sense that they would disable the feature.

It doesn't look like there are any other traces going away from it, so most likely the connection is intentional.

[ComputerGeek]

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

Ok and pin one needs to be used for it to function correct? Because I don't see any traces leading away from pin 1 other than possibly to the smd cap.

[tom66]

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

Ok and pin one needs to be used for it to function correct? Because I don't see any traces leading away from pin 1 other than possibly to the smd cap.

Yes. It handles the soft start of the power supply.

[budm]

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

I am late on this thread and would like to know where it is at this point with the new IC installed. It sounds like the PS_ON is OK, Standby 5 volt is OK, but no 5v main, 12v, or 24Coming out from the main switching section.
Can I please get the clear picture in the red area, I believe the SMPS IC may not getting the VCC feeding it if I am correct.

[budm]

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

I just looked at the spec of the IC, so please also get the pictures for this section also so I can see where pin 12 is connected to, thanks.

[tom66]

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

budm, ComputerGeek found that the IC had a 5.5 ohm short between Vcc and ground. And no short between the pads with the IC removed. That is why he is replacing it at the moment.

[budm]

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

Thanks TOM66, it is just a very long thread and it is hard to keep up as to where he is at at this point.

[ComputerGeek]

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

^^^ Indeed it is a long thread! Anyway,

"Houston we have a Problem!"

Well I have Good and Bad news.

First the Good the Power supply is working, I replaced the IC and three of the 1000uf Caps I ordered them because they still seemed like they might be bulged, I know It is hard to tell with just a Photo. Anyway, I replaced those components and Installed the board back in to the Tv.

Bad News the Tv only stayed on for about a minute then the screen started flickering and there was a popping noise coming from the speakers, I immediately cut the power to the TV. However, during the one minute I was able to access the menus fine. Waited a few minutes and tried it again, this time I plugged a PS2 in and video and sound worked, but after about 30 seconds the screen went black and the was a pop in the speakers simultaneously. Also, note here that the Tv still stays on both the Logo and the Power light on. In Addition, after the pop and the screen shuts off there is no video or sound. (I Think this may be a clue.) So even thought the Logo is lit there is No Sound, There is sound before the Pop.

Finally, the condition has worsened to turn on, make the pop and the flicker for one second and then black, the power button can be used to turn the Tv off and on, however the second time the Tv is powered up with the power button there will be no flash or pop. However, if you unplug the TV from the wall and let the boards drain, then plug it back in the pop and the flicker happen again.

I am totally unsure, but this is just a thought I had. If the inverter had the problem would this take the sound and the picture out, or just the picture? Would It be more likely that the Power Supply is providing unstable voltages or the Main board has a problem?

Thanks for all the Help!

[tom66]

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

What caps did you use and why did you replace caps that were perfectly fine?

[budm]

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

The 12vdc and the 24vdc are generated by the circuits that you just had replaced the IC, 12VDC is used for the sound section, the 24 is used for the backlights inverter circuits. You should hook up a 12v lamp to the 12v output and see if it goes out (the 24 should also goes away since it is from the same transformer)

[ComputerGeek]

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

tom66 I used these, I don't know, they seemed like they were slightly bloated in person.

http://search.digikey.com/scripts/Dk...81-ND&x=9&y=14

budm are you saying that I should measure the 12v and 24v outputs with my DMM?

[budm]

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

Yes, set DMM to DC volt mode, I like using lamp along with the meter so I can easily see if it is on steady or not.

[tom66]

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

tom66 I used these, I don't know, they seemed like they were slightly bloated in person.

http://search.digikey.com/scripts/Dk...81-ND&x=9&y=14

budm are you saying that I should measure the 12v and 24v outputs with my DMM?

Okay, just as long as you didn't use RadioShack specials . They look suitable. Check your solder joints under these caps.

[ComputerGeek]

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

Yes, set DMM to DC volt mode, I like using lamp along with the meter so I can easily see if it is on steady or not.

OK I got to take the covers back off I'll post results back after I get home tonight.

Okay, just as long as you didn't use RadioShack specials . They look suitable. Check your solder joints under these caps.

Solder joints were already checked under a Magnifier, they were fine.

And I know better than to use CellShack Specials if your getting more than one Component its more cost effective to go with, Digikey. If they even have what your looking for!