Toshiba 32DT2U1 with unique problem

[Jwh1o1]

I have a Toshiba 32DT2U1 television that will turn on and everything works but the screen. The sound plays from whatever input selected just no picture. I have searched this forum and found 3 other posts but none of the issues are like mine. I have tried the disconnect power and hold power trick. I also reset the TV using the reset menu. Since everything else is working I am presuming it is not a power board/capacitor issue? I checked the voltages they are all spot on according to the other 3 posts. Does anyone think this could somehow be an eeprom issue or do you think I just have a dead display? I found a new display for $100 but i do not want to get it until I know with reason if it may work. Or would it be better to scrap it?

Here is the display.

[dick_barton]

Re: Toshiba 32DT2U1 with unique problem

Can you post pictures of your boards.
Have you checked if you have a supply to the fuse on the Tcon board?
Does the fuse have the same voltage on both sides?
Are the backlights on?

[CapLeaker]

Re: Toshiba 32DT2U1 with unique problem

try the tv tuner, the OSD menu etc... to see if something comes up on the screen.

[LITEZONER]

Re: Toshiba 32DT2U1 with unique problem

sounds like you have a bad inverter board, but 1st make sure you are getting or not getting voltage to the backlight, if you are getting steady voltage to the backlight then the backlights are probably bad, if not then i think you have an inverter issue.

[Jwh1o1]

Re: Toshiba 32DT2U1 with unique problem

Here are some pictures of the boards sorry they are not very good. It is my day off and trying to get good pictures with a 18 month old on your arm is a bit hard. How do I measure the voltage from the inverter board to the lamps? This board slides into 8 white clips on the display back. and what voltage will it be?

As far as the on screen menu nothing shows up even when I press menu. I tried to see if the LCD is working with the bright light method but I do not think my light is bright enough to work. The Back lights do not come on.

[Khron]

Re: Toshiba 32DT2U1 with unique problem

First of all, you don't wanna stick your multimeter on the inverter outputs - there's anywhere between 600v and 1200v AC RMS over there, likely to blow just about any "normal" multimeter.

https://www.tvpartsforsale.com/asset...K101V1550I.jpg

I just about managed to make out the markings on your power supply board, and found a better photo of it. As i suspected, the pinouts are pretty clearly marked, on the board.

The first 4 pins (counting from the top of connector P803) should be 24V, the next 4 should be ground pins. When the TV is on (ie. you can hear sounds etc), you should measure about 24v there (+/- 5-10% or thereabouts).

If that's ok, you'll want to check the BL_ON signal, which would seem to be on the 3rd pin from the bottom, on the same connector. Normally that should be 3.3v or 5v (relative to ground), for the backlight to be signalled to turn on.

I found what might well be the inverter board that's in this model (or at least a seemingly very similar one) - http://i.ebayimg.com/images/i/122138...-1/s-l1000.jpg

I don't like those two electrolytic caps in there... That Samyoung logo spells trouble, especially since those inverters run pretty warm.
There's a certain chance the backlight could come back to life after replacing those two capacitors.

[Jwh1o1]

Re: Toshiba 32DT2U1 with unique problem

First of all, you don't wanna stick your multimeter on the inverter outputs - there's anywhere between 600v and 1200v AC RMS over there, likely to blow just about any "normal" multimeter.

https://www.tvpartsforsale.com/asset...K101V1550I.jpg

I just about managed to make out the markings on your power supply board, and found a better photo of it. As i suspected, the pinouts are pretty clearly marked, on the board.

The first 4 pins (counting from the top of connector P803) should be 24V, the next 4 should be ground pins. When the TV is on (ie. you can hear sounds etc), you should measure about 24v there (+/- 5-10% or thereabouts).

If that's ok, you'll want to check the BL_ON signal, which would seem to be on the 3rd pin from the bottom, on the same connector. Normally that should be 3.3v or 5v (relative to ground), for the back light to be signaled to turn on.

The first 4 read 24.4 volts and BL on is 4.8v. I wont risk my Multimeter on the other, as it only goes up to 600 max for 10 seconds. There is no flicker when the tv is turned on at all. Yea the boards are very detailed on what is where and voltages!

[Khron]

Re: Toshiba 32DT2U1 with unique problem

See the additions i've edited in my previous post

That metal cover that's over the inverter board should be held in with a few screws - any chance you could uncover it and identify those capacitors?

[Jwh1o1]

Re: Toshiba 32DT2U1 with unique problem

See the additions i've edited in my previous post

That metal cover that's over the inverter board should be held in with a few screws - any chance you could uncover it and identify those capacitors?

Yea just seen the edits. They are the very same. The caps do store current but I do not have a tester for them unfortunately.

[Khron]

Re: Toshiba 32DT2U1 with unique problem

What are the markings on them?

For what it's worth, the samyoung logo looks like this: http://i.ebayimg.com/images/a/(KGrHq...g~~/s-l300.jpg (although if smaller, it won't have the name written, only the symbol).

Also the series (3-letter code) would help, as well as the value (uF) and voltage rating.

Are their tops domed / bulged?

[Jwh1o1]

Re: Toshiba 32DT2U1 with unique problem

No leaking fluid from bottom top is flat and no bulging that I see. There is lettering on the back but I can not see all of it. 105c temp rating I think. I even went and checked all the diodes I could.

[CapLeaker]

Re: Toshiba 32DT2U1 with unique problem

If there is no flicker of the backlights at all, either the BLon signal is missing, the fuse is blown on the inverter board, no or not enough power to the inverter board, or the backlights control ic on the inverter board is bad.
Someone had fiddled around with that board before.

[Jwh1o1]

Re: Toshiba 32DT2U1 with unique problem

If there is no flicker of the backlights at all, either the BLon signal is missing, the fuse is blown on the inverter board, no or not enough power to the inverter board, or the backlights control ic on the inverter board is bad.

The voltages are all right to the board. The fuse has voltage on both sides. I can not check the IC though.

I am gonna guess there is no way to check the back lights without a new inverter to test?

We got the TV from Walmart 4 years ago. I have been to scared to work on flat panels until now I am stuck watching a 27in crt and I figured why not see what I can do.

[CapLeaker]

Re: Toshiba 32DT2U1 with unique problem

There is such a jig like a ccfl tester, that one can buy. At this point I'd be either getting a new control ic or better a replacement inverter board.

Even with a ccfl gone, the inverter should power up the rest of the ccfls for a second before the shut down kicks in. Having not even a blink, indicates what I mentioned in my last post.

[Jwh1o1]

Re: Toshiba 32DT2U1 with unique problem

Well I found a board for 15 I am going to give it a go when I get the extra money. Thank you everyone for the help!

[Khron]

Re: Toshiba 32DT2U1 with unique problem

I don't trust that Samyoung NXH there, but that Rubycon next to it looks "out of place", and its solder joints don't look 100% "factory" either.

[Jwh1o1]

Re: Toshiba 32DT2U1 with unique problem

http://www.ebay.com/itm/Toshiba-Sams...25.m3641.l6368
SSI320_4UA01 is the part number
All the boards I have found through replacement sites have the same yellow/black combination? And they all look like crap soldering lol. If we could see the boards before we buy stuff many of us would walk away without another thought.

[Khron]

Re: Toshiba 32DT2U1 with unique problem

I'd give replacing those two caps a shot, before springing for a whole new inverter.

Although, while you have the metal cover off it, you might as well test those four MOSFETs next to them as well.

Multimeter in diode test mode, black probe on the metal tab, ie. the drain (on each) and red probe on the bottom-right leg, ie. the source pin (assuming the tab's pointing "upwards"). Expect to see readings around 0.6xx volts if they're good.

http://image.slidesharecdn.com/yolei...?cb=1401274088