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Old 01-09-2012, 02:25 PM   #1
vwmeche94
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Default Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

BC.Net,

We have a Dynex DX-LCD32-09 TV with the following:

S/N 1291LC32HV40H13961

LOT 470585

XHT 081139

Last week, my two youngest were watching a show and the screen all of a sudden went white; you can make out images and there is sound, but no color.

I contacted Dynex Customer Support and they keep trying to force me to Geek Squad. I know the fix is less than what I'd be paying for them to troubleshoot.

I've seen at least one other post about this model on the forum, so others have experienced similar issues.

Can anyone tell me where my problem may lie so I can get my TV back into normal operation?

Thank you,
vwmeche94
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Old 01-09-2012, 02:38 PM   #2
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Most likely the problem is on the T-con. This is a $20 part and is easy to replace.
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Old 01-09-2012, 03:27 PM   #3
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

TOM66,

Thank you for the reply. Is the $20 part the entire T-CON or a component on the board?

I have already opened the tv up and taken the following pictures (attached).

I don't think I got a picture of the T-CON; I believe I got the mainboard for cable connections and the power supply board?

Where can I find the T-CON board for purchase at $20?
Attached Images
File Type: jpg 100_2225.JPG (121.5 KB, 75 views)
File Type: jpg 100_2226.JPG (215.5 KB, 58 views)
File Type: jpg 100_2227.JPG (115.0 KB, 55 views)
File Type: jpg 100_2228.JPG (92.2 KB, 49 views)
File Type: jpg 100_2230.JPG (81.8 KB, 49 views)
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Old 01-09-2012, 03:50 PM   #4
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Quote:
Originally Posted by vwmeche94 View Post
Where can I find the T-CON board for purchase at $20?
A T-con looks like this. It is underneath one of your metal shields. This ebay auction ended

http://www.ebay.com/itm/320819832815

but the t-con listed for $12 USD with $6 shipping. If the problem is the t-con, you can always ask the seller to relist or "buy it now" for $25.

Make sure the revision numbers, part numbers, are all the same before ordering.

Replacing it is easy, but be careful as the connectors are super fragile.

PS. I can't voucher for seller, but they have 100% feedback.
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Old 01-09-2012, 04:20 PM   #5
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Quote:
Originally Posted by vwmeche94 View Post
TOM66,

Thank you for the reply. Is the $20 part the entire T-CON or a component on the board?

I have already opened the tv up and taken the following pictures (attached).

I don't think I got a picture of the T-CON; I believe I got the mainboard for cable connections and the power supply board?

Where can I find the T-CON board for purchase at $20?
The main board is generally the one with the inputs on it (the green one); the power supply is the one connected to the mains input in your case the white-cream board.

For most beginners I suggest replacing the whole board. You can do a component level repair on it but if you've never done that before you will find it very difficult. I still find it very difficult, even though I have a lot of the necessary tools and skills. I recently succeeded repairing a T-con on a Samsung LCD (failed LDO...), but it took me 50 minutes and the T-con was only 18 including shipping, if I weren't a poor student I'd probably have just bought a whole new one!

$20 was an estimate but I've never seen a T-con for more than $30. They are a common fault in LCD TVs.

The T-con is likely under where I have highlighted. Just to be sure, follow the LVDS cable, highlighted in blue, from the main board to the T-con. Unfortunately, it looks like the design of this TV doesn't lend to easy service - you're going to have to remove the wall mount bracket and probably the power supply.

Just to confirm, post a picture of the screen with the problem. I'm thinking of one other strange possibility that could cause a lack of colour - a failed chroma output or an out of tolerance crystal, but that's very difficult to diagnose. Check your set-top box with another TV, if possible. Poor chroma will be easy to confirm: it will look like there is a sea of dots moving around each edge (dot crawl.) If, when you select a menu on the TV, it too has a lack of colour and is white-out, then it's almost certainly a T-con problem.
Attached Images
File Type: jpg T-con is here.jpg (126.1 KB, 94 views)

Last edited by tom66; 01-09-2012 at 04:26 PM..
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Old 01-19-2012, 10:31 AM   #6
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

T66 and RetCaps,

Thanks big time for the feedback guys!

I went and looked where shown and found the T-Con. I have no fear of trying to perform component level repairs; I'm a mechanical engineer by training, so any electrical knowledge gained will fit perfectly into my "toolbag."

I will order from the link shown at ebay though, make repairs (hopefully successful) to my original board and sell for a few bucks or just give away for cost of shipping (since the knowledge was given freely!)

Any advice on where and how I can begin to make the board level repairs would be greatly appreciated.

Just as a sanity check, I did upload pictures of how the TV currently performs.

Regards,
vwmeche94
Attached Images
File Type: jpg IMG_20120115_114416.jpg (87.3 KB, 67 views)
File Type: jpg IMG_20120115_114434.jpg (98.9 KB, 62 views)
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Old 01-19-2012, 11:24 AM   #7
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

If you post a picture of your board, then we can suggest things that could cause this. There are two main voltages generated on the T-con from the 5V input supply. They are the boost supply (typically 15-35V) and the negative supply (typically -5V to -15V.) One of these has probably stopped working.
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Old 01-21-2012, 06:43 PM   #8
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

T66,

Here is the pic of my T-CON board... sincere thank you!
Attached Images
File Type: jpg IMG_20120121_192502.jpg (264.8 KB, 80 views)
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Old 01-21-2012, 10:18 PM   #9
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

That would be the inverter board (takes low voltage from the power supply and boosts it to 700-1500V to run the backlight).

The t-con is the board that has fine ribbons going to the TFT panel of the TV. Should be somewhere under the metal covers in the area circled in red in this picture:
http://www.badcaps.net/forum/attachm...3&d=1326151166
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Old 01-27-2012, 04:29 PM   #10
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Okay, realized you meant I had to go deeper... here we go.
Attached Images
File Type: jpg 100_2231.JPG (61.8 KB, 69 views)
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Old 01-27-2012, 04:47 PM   #11
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Quote:
Originally Posted by vwmeche94 View Post
Okay, realized you meant I had to go deeper... here we go.
Perfect. Any numbers on the board that might be a part code?
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Old 01-28-2012, 09:08 AM   #12
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

tom66,

I believe you're asking about these numbers (see image and below):
  • CPT 320WF01C
  • 307
  • E187565
  • VB S291010
Attached Images
File Type: jpg PART NO.jpg (82.2 KB, 50 views)
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Old 01-29-2012, 05:54 PM   #13
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

I noticed on ebay that there are different alphanumerics of different T-Cons in the "VB S291010" place. I.E., "WA C17V011".

Is this critical to match exactly?
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Old 01-30-2012, 12:37 AM   #14
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Quote:
Originally Posted by vwmeche94 View Post
I noticed on ebay that there are different alphanumerics of different T-Cons in the "VB S291010" place. I.E., "WA C17V011".

Is this critical to match exactly?
Probably - the T-con is specific to the LCD panel. It may work, you can't be sure.

By the way - someone else has your problem: http://www.riddledtv.com/forums/32-d...ure-t2210.html
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Old 01-30-2012, 10:43 AM   #15
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Another alternative is to try and troubleshoot your t-con, but for this you will need a multimeter and some basic knowledge of how to use it. If you do, then just post some bigger pictures of the t-con so we can point out which components to check.
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Old 01-31-2012, 09:48 AM   #16
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Here is a larger picture of the T-Con.
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File Type: jpg 100_2233.JPG (224.2 KB, 72 views)
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Old 02-03-2012, 09:42 AM   #17
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Hey Momaka and Tom66, I uploaded the larger T-Con pic as instructed... what equipment and where can I begin checking?

Thank you again,
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Old 02-03-2012, 12:31 PM   #18
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Hi vwmeche94.
For now, all of the equipment you'll need is a multimeter (preferably a digital one).
If you're not sure how to use one, this video shows some of the basics:
http://www.youtube.com/watch?v=bF3OyQ3HwfU

But before you begin, note the following about measuring resistances:
- if you have a manual multimeter, a "1" on the left side of the screen of your multimeter indicates an open circuit and/or out-of-range readings (i.e. the resistance you're trying to measure is higher than what your multimeter can measure on that setting).
- if you have an auto-ranging multimeter, a "OL" on the screen indicates an open circuit (i.e. the resistance between the two test points you're trying to measure is very very high or the two test points are not connected at all)
- a "1.00" or "1.000" is an actual resistance reading and...
- always note the units and scale of the resistance you're measuring. A random number such as "3.45" doesn't mean anything. The base unit for resistance is the Ohm (Ω).
1 KiloOhm (or 1 KOhm) = 1000 Ohms.
1 MegaOhm (or 1 MOhm) = 1000000 Ohms.
- A short-circuit (very very low resistance or almost none) will show close to "0.00" Ohms.

First and foremost, check fuse F1 (Lower center of the picture you posted. Has an "N" written on it. It's right next to the right side of the connector). To check the fuse, select continuity on your multimeter and place the probes across the two terminals on fuse F1. A good fuse will show 0.00 or close depending on the accuracy and quality of your multimeter (mine is cheap and shows 2.00). A bad fuse will give you a "1" on the left side of the screen or "OL".

If your fuse is bad, then you do not need to do the voltage measurements I ask for below. If the fuse is good, do both the resistance and voltage measurements.

...

There are several voltage rails on the t-con that need to be checked. These are VDDA, VDDD, VGL, and VGH. Your t-con has test points for those rails where you can put the multimeter probes. See attached picture.

First, you should check the resistance between each of these test points with respect to ground. Ground is connected to any metal part of the case of your TV. The exposed copper area around the screw holes on the t-con is one place where you can use as a ground point. When measuring, keep the black (negative) multimeter probe on ground, not the red (positive) one. The red probe you move to each test point, one at a time. Also, make sure the TV is turned OFF and unplugged!
Let's start with measuring resistance for VDDA... Select resistance setting on your multimeter. If it's a manual multimeter, choose the 200 Ohm scale (note that for some, if not most test points, you will likely get a "1" on the left side of the screen). Place black probe on ground and red probe on the exposed copper circle right above where it says "VDDA". Note the resistance and write it down. Do this for all of the other test points and post the results here.

Next, you will be measuring the voltages on these test points. For this, you will need to plug in the TV and turn it ON. BE CAREFUL and avoid touching any parts on the inverter or the power supply boards with your fingers as those have some dangerous voltages (the t-con is safe to touch, though).
Just as you did with measuring the resistances, place the black probe on ground and the red probe on each test point. Note the voltage and post it here.

Also note if any component on the t-con is overheating (by overheating I mean burn-your-finger type of hot).
Attached Images
File Type: jpg t-con for Dynex DX-LCD32-09.jpg (126.6 KB, 70 views)

Last edited by momaka; 02-03-2012 at 12:40 PM..
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Old 02-08-2012, 12:06 PM   #19
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Quote:
Originally Posted by momaka View Post
Hi vwmeche94.
For now, all of the equipment you'll need is a multimeter (preferably a digital one).
If you're not sure how to use one, this video shows some of the basics:
http://www.youtube.com/watch?v=bF3OyQ3HwfU

But before you begin, note the following about measuring resistances:
- if you have a manual multimeter, a "1" on the left side of the screen of your multimeter indicates an open circuit and/or out-of-range readings (i.e. the resistance you're trying to measure is higher than what your multimeter can measure on that setting).
- if you have an auto-ranging multimeter, a "OL" on the screen indicates an open circuit (i.e. the resistance between the two test points you're trying to measure is very very high or the two test points are not connected at all)
- a "1.00" or "1.000" is an actual resistance reading and...
- always note the units and scale of the resistance you're measuring. A random number such as "3.45" doesn't mean anything. The base unit for resistance is the Ohm (Ω).
1 KiloOhm (or 1 KOhm) = 1000 Ohms.
1 MegaOhm (or 1 MOhm) = 1000000 Ohms.
- A short-circuit (very very low resistance or almost none) will show close to "0.00" Ohms.

First and foremost, check fuse F1 (Lower center of the picture you posted. Has an "N" written on it. It's right next to the right side of the connector). To check the fuse, select continuity on your multimeter and place the probes across the two terminals on fuse F1. A good fuse will show 0.00 or close depending on the accuracy and quality of your multimeter (mine is cheap and shows 2.00). A bad fuse will give you a "1" on the left side of the screen or "OL".

If your fuse is bad, then you do not need to do the voltage measurements I ask for below. If the fuse is good, do both the resistance and voltage measurements.

...

There are several voltage rails on the t-con that need to be checked. These are VDDA, VDDD, VGL, and VGH. Your t-con has test points for those rails where you can put the multimeter probes. See attached picture.

First, you should check the resistance between each of these test points with respect to ground. Ground is connected to any metal part of the case of your TV. The exposed copper area around the screw holes on the t-con is one place where you can use as a ground point. When measuring, keep the black (negative) multimeter probe on ground, not the red (positive) one. The red probe you move to each test point, one at a time. Also, make sure the TV is turned OFF and unplugged!
Let's start with measuring resistance for VDDA... Select resistance setting on your multimeter. If it's a manual multimeter, choose the 200 Ohm scale (note that for some, if not most test points, you will likely get a "1" on the left side of the screen). Place black probe on ground and red probe on the exposed copper circle right above where it says "VDDA". Note the resistance and write it down. Do this for all of the other test points and post the results here.

Next, you will be measuring the voltages on these test points. For this, you will need to plug in the TV and turn it ON. BE CAREFUL and avoid touching any parts on the inverter or the power supply boards with your fingers as those have some dangerous voltages (the t-con is safe to touch, though).
Just as you did with measuring the resistances, place the black probe on ground and the red probe on each test point. Note the voltage and post it here.

Also note if any component on the t-con is overheating (by overheating I mean burn-your-finger type of hot).
Hello Momaka.

I have been following your posting intensively. I am on a US Navy ship who just deployed. We have the exact same problem as listed by vwmeche94. Ordering a t-con board would take a long time to get to us so we would prefer to fix this POS Dynex . Here are our resistance readings and voltages.
VDDA: 7.24 kOHM 15.3 VDC
VDDD: 11.73 kOHM 3.36 VDC
VGL: 23.37 kOHM -6.25 VDC
VGH: 57.8 kOHM 25.52 VDC

We did make sure nothing felt hot to the touch. Anxiously awaiting your response.
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Old 02-09-2012, 12:13 AM   #20
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Default Re: Dynex DX-LCD32-09 Power, sound, but screen/picture is bright white no color

Hi iceman3k,

Seems like the power supply section of you t-con is working fine. The resistances on those voltage rails don't indicate that anything has a problem and the voltages are pretty much what you would find on a typical working t-con.

Two other threads came up not too long ago for LCD monitors that had the same color issue. The t-con voltages for those monitors were also fine. The pattern I'm starting to see here, unfortunately, suggests that this problem may be more complex. Moreover, I'm no longer sure if this problem is a t-con issue or a video/logic board issue. I guess the next step would be to check all of the voltage regulators on the video/logic board to see if they are putting out the proper voltages (I see at least 5 voltage regulators from vwmeche94's pictures). If you have an ESR meter, perhaps check some of the caps next to those regulators (and some of the bigger caps as well).

Not sure what else to suggest. If nothing else turns up, then you might just have to replace the t-con and hope that was the issue .

Last edited by momaka; 02-09-2012 at 12:15 AM..
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