Dell W3201c LCD TV

[airscapes]

Hi, first time poster, stumbled on this forum searching for tips on repairing this TV. It was manufactured in 2005 and from the info I can find had problems with the power supply and audio board. This one was a free bee from a guy on Craigs list so I have nothing invested to speak of.

History: TV will power off whenever it feels like it. Sometimes it will start back up if you hit the power button 2 times and runs fine for hours.
I pulled it apart and looked at ever single board for signs of a bad component. In researching (this is the first LCD TV I have played with) I found out about the feed back circuits and after much time looking at boards I was about to give up. The sound board was also bad so If I could not get the TV to be reliable why bother with the sound.
One of the last things I did was pull off the gray rubbery gunk they had smeared over the secondary transformer output leads. Shortly after this the TV went into a no start condition. The 5v and 12v LED on the main board would light and then go out when the power was turned on. I could hear a click coming from that transformer and from the inverter board when the power button was pushed. I remove the inverter board and measured the resistance of the transformers on the board and all were identical.
Again ready to give up I tried heating the secondary transformer on the power supply board with a hair dryer. 60 seconds, hit the power and bang ran all day.
Next day, no start, heat it up and runs all day.

I pulled the board off, resoldered all connection on the transformer and all large connections on the back of the board.
The TV worked for several days flawlessly.
Reassembled all 200 screws, took it upstairs and stated using it. Next day, shut off after about 5 minutes. .. powered up later on, shut off in a few minutes..

Next step is to take it back to the basement and disassemble again..
Any one run into this junker and have success repairing it?
I don't know if I had 2 different problems (no start and shutdown) of if they are one in the same.
Only test equipment is a Fluke 115 and of course the hair dryer

The power supply board number is FSP FSP200-5F01

Thanks in advance!
Doug

[retiredcaps]

Re: Dell W3201c LCD TV

Next step is to take it back to the basement and disassemble again..

1) Post clear focused pictures using the manage attachments feature. Please do not post pictures inline as they slow down the loading of pages.

2) For best picture quality and clarity take your boards to a window on a sunny day, turn flash off, and use macro mode. Take a top down view of all your boards (front and back). Make sure the photo is legible so that we can read the PCB printing clearly. A shutter speed of 1/125 or faster will produce nice clear focused pictures. Try to get a photo that is 2000x2000 resolution or as close as possible.

3) Here is an example of the pictures we want (including an overall picture so we can see how things are connected).

https://www.badcaps.net/forum/showpo...94&postcount=1

[airscapes]

Re: Dell W3201c LCD TV

1) Post clear focused pictures using the manage attachments feature. Please do not post pictures inline as they slow down the loading of pages.

2) For best picture quality and clarity take your boards to a window on a sunny day, turn flash off, and use macro mode. Take a top down view of all your boards (front and back). Make sure the photo is legible so that we can read the PCB printing clearly. A shutter speed of 1/125 or faster will produce nice clear focused pictures. Try to get a photo that is 2000x2000 resolution or as close as possible.

3) Here is an example of the pictures we want (including an overall picture so we can see how things are connected).

https://www.badcaps.net/forum/showpo...94&postcount=1

You want me to disassemble the entire unit and take photos of all the boards or just the suspect power supply?

[airscapes]

Re: Dell W3201c LCD TV

Here are a couple of pictures of the complete unit (audio board is a Frankenfix) and the top and bottom of the power supply. Sorry for the poor lighting no sun expected for a few days..

[retiredcaps]

Re: Dell W3201c LCD TV

Again ready to give up I tried heating the secondary transformer on the power supply board with a hair dryer. 60 seconds, hit the power and bang ran all day.

1) There are 3 transformers on the power board. Which one are you calling secondary?

Only test equipment is a Fluke 115 and of course the hair dryer

2) I see Fluke 115 does capacitance measurement. You may want to measure the caps "in circuit" around area where you used the hair dryer. I know the Fluke 115 won't measure ESR though.

3) Does the hair dryer trick always start the TV?

4) The overall pic is important to understand the relationship between boards. Thanks for including it.

5) On the small blue board (just left of the power board), there seems to be one cap that is bloated (most left cap). Or is that just lighting or angle of the photo?

[airscapes]

Re: Dell W3201c LCD TV

1) There are 3 transformers on the power board. Which one are you calling secondary?



2) I see Fluke 115 does capacitance measurement. You may want to measure the caps "in circuit" around area where you used the hair dryer. I know the Fluke 115 won't measure ESR though.

3) Does the hair dryer trick always start the TV?

4) The overall pic is important to understand the relationship between boards. Thanks for including it.

5) On the small blue board (just left of the power board), there seems to be one cap that is bloated (most left cap). Or is that just lighting or angle of the photo?

Good morning and thanks for looking.
1. The roundish transformer that seems to feed the rest of the unit is what I was calling the secondary.
2. Yes I used the meters capacitance function to test the capacitors on the original sound board and even removed them from the board but sound is no longer an issue.
3. I am starting to believe the "no start" and intermittent shutdown are 2 separate issues. As I said, I thought it was fixed after resoldering the power supply, however after Moving the unit to the Kitchen and then moving it around a few time, the shutdown after cold start returned the next day. Now after more moving around and disassemble for the photo shoot, it has not shut down. I have not dug into the pannel deep enough to get a look a the back lamp. I don't even know if I can or if it is a sealed unit. Seem almost like a feedback shutdown now since it will restart after pushing the power button 2 times.. This is why the original owner gave this tv away.

5. I just looked at them and they all look the same. There is some white dust on them which had been wiped off near the top by my finger so could be causing the Illusion or maybe just the light.

Thanks again for you assistance.. btw, unit started right up and an hour later still running.. this is why I got out of the Automotive repair business!!

[retiredcaps]

Re: Dell W3201c LCD TV

On the backside, I circled a number of what I think look like questionable solder joints (particulary ring cracks). There could be more, but you have the best view of the board.

You may want to resolder/reflow them.

[airscapes]

Re: Dell W3201c LCD TV

I will resolder all of them tonight. Sorry what do you mean by ring cracks?
Also, when resoldering these, is it best to remove the old solder or just add a bit of flux and new solder?
I did add a touch of flux and reheat the large connectors adding a bit more solder since I know the big connectors can require more heat and end up being cold..
TV is still on since 7:30AM.
Thanks again!

[retiredcaps]

Re: Dell W3201c LCD TV

Sorry what do you mean by ring cracks?
Also, when resoldering these, is it best to remove the old solder or just add a bit of flux and new solder?

See

http://workmanship.nasa.gov/lib/insp...uirements.html

for examples of poor soldering.

I sometimes reflow and sometimes resolder. I think removal of the old solder and adding fresh solder is the best.

If you have 200 screws and don't want to take it apart again, I think it would be best to do it "right".

[airscapes]

Re: Dell W3201c LCD TV

Well now I've gone and done it!
I remove the PS and resoldered the connections you suggested and attempted to remove some of the flux with alcohol. Rather than reinstalling the PS I continued to disassemble the unit to gain access to the back lights. This involved removing a bezel that I had previously not removed and unclipping the LCD panel. Once I lifted the panel off I could lift the diffusers and see the tubes. Looked ok to me.. so back together it went.
I then removed the blue board to see if I could test the capacitors with the Fluke while still attached to the board. Didn't work out so well, could not get readings on some and seemed to read 4 together when checking at another spot. The board must have the traces sandwiched inside, there are none on the bottom. So back it went..
Fired it up and NADA...
There are 3 leds on the main board, 5v 5v+ 12v+
They all light but no picture. In the past with my no start condition, the 5v+ and 12v+ would blink on and off. Now they stay on as if the unit was running.
I put the stand back on and tuned off the lights and fired it up, gave it a shake and the back lights started flashing in a steady fashion as if trying to start..
I check the inverter board and there are 4 brown wires and 4 black, each brown has 24v and each black is a ground. last 3 wires am not sure as to what they should read.
Also notice the power supply does not make as much noise as it did in the past.. not sure what exactly that means..
I am about to give up and stop messin with this thing.. wife will have to do without a TV in the kitchen.. been 18 years without.. not the end of the world..

[Hobby 1]

Re: Dell W3201c LCD TV

Give up and scrap this garbage. All Dell TV's are overpriced garbage, unfixable and not worth trying. Even Dell considers them disposable TV's. Do an internet search on any of their models and you will see the problems that most people have once the warranty is over. Even their own forums have many unhappy customers that will never buy another Dell.... I have this model and another, in for repair. Intermittent and different problems every time you touch it.

[airscapes]

Re: Dell W3201c LCD TV

Give up and scrap this garbage. All Dell TV's are overpriced garbage, unfixable and not worth trying. Even Dell considers them disposable TV's. Do an internet search on any of their models and you will see the problems that most people have once the warranty is over. Even their own forums have many unhappy customers that will never buy another Dell.... I have this model and another, in for repair. Intermittent and different problems every time you touch it.

I know, I but I am kind of attached to it now..
Pulled it apart again and can not see anything physical wrong with the back light tubes but I am guessing that is where the issues is. When I power it on the back light does nothing, but if I give it a good hard shake or smack it, they start flashing. I have a green wire which is pulsing 0 to almost 5 volts. Brown wire are 23.89v and drop slightly as the back light pulses. Seems like it could still be power supply. However watching the back light pulse there looks to be 1 or 2 tubes (can not see for sure because the or the LCD) at the bottom that are not lighting when it blinks..
Does anyone know what the input voltage for the transformers on the inverter board should be? Any way to test the tubes with a vom... I assume not..

[Hobby 1]

Re: Dell W3201c LCD TV

The lamps cannot be tested with a meter. And it is dangerous to test the inverter transformers with a meter while they are working. I know one person who destroyed his meter doing so.
The proper way to test the lamps is in circuit when the lamps power on. The bad lamp will not light. Repest the test to be sure because it gets very bright. Mark the position of the bad lamp with a marker or some green tape, don't mark the lamp!. Follow the lamp to the transfomer. Check that transfomer and circuitry. You can sometimes switch wires to a different lamp and see if the problem moves to the other lamp or if the same lamp fails to light. If the problem moves, its the transfomer or its circuitry. If the same lamp fails to ignite, its the lamp. Change out the bad parts. And Dell does not sell any parts for repairs...again, they consider their products as disposable, not worth fixing.

[airscapes]

Re: Dell W3201c LCD TV

The lamps cannot be tested with a meter. And it is dangerous to test the inverter transformers with a meter while they are working. I know one person who destroyed his meter doing so.
The proper way to test the lamps is in circuit when the lamps power on. The bad lamp will not light. Repest the test to be sure because it gets very bright. Mark the position of the bad lamp with a marker or some green tape, don't mark the lamp!. Follow the lamp to the transfomer. Check that transfomer and circuitry. You can sometimes switch wires to a different lamp and see if the problem moves to the other lamp or if the same lamp fails to light. If the problem moves, its the transfomer or its circuitry. If the same lamp fails to ignite, its the lamp. Change out the bad parts. And Dell does not sell any parts for repairs...again, they consider their products as disposable, not worth fixing.

Thanks, I know there will be no getting new parts, I am working on getting another TV with a damaged LCD. I only want to spend $20 tops but the owner wants $80. Seems that everything works on it.. just has a cracked LCD..
In the mean time, just wanted to get this figured out for my own satisfaction.
I assume if all lamps fail to light then the tv will not turn on (no image on the panel).

[Hobby 1]

Re: Dell W3201c LCD TV

If one lamp is bad, the others will light and then go out when the current monitor circuit sees an imbalance. That gives you a flash of 1 - 3 seconds. Enough time to spot the bad lamp. If none of the lamps light (no flash) then the problem is elsewhere. Is the other TV the same model? either way, $80 is way too much for a broken screen set, especially a Dell. If it is not the same model, the lamps may be different. I found that out the hard way. $20 is fair, $40 if you really want to try and fix this thing.

[retiredcaps]

Re: Dell W3201c LCD TV

4) The overall pic is important to understand the relationship between boards. Thanks for including it.

I just relooked at the overall pic. It seems that there is a board (probably inverter board) just to the left of the picture. This will be a longish board with multiple inverter transformers and possibly bad caps on it.

I can see the connector to the board on the very lower left bottom of the picture.

You can measure the resistance of these inverter transfomers (with power off and lcd unplugged).

[airscapes]

Re: Dell W3201c LCD TV

I just relooked at the overall pic. It seems that there is a board (probably inverter board) just to the left of the picture. This will be a longish board with multiple inverter transformers and possibly bad caps on it.

I can see the connector to the board on the very lower left bottom of the picture.

You can measure the resistance of these inverter transfomers (with power off and lcd unplugged).

I have done that in the past on this set. I had no idea what the resistance should be but I compared every transformer and all were identical.

I do believe my current problem is mechanical.
I just finished messing with it at lunch.
1. meter connected to the green wire on the inverter board connector
2. power on unit
3. very low voltage at this wire, 24v on the 4 brown wires.
4. Tap the case on the power supply side (not slam it but a medium bump whit a screw driver) and the voltage starts to cycle 0-almost 5v and back lights flash in sync with this.
This is repeatable.
I have removed the PS complete and let it hang so as not to be contacting the case and I get the same results. My assumptions is a problem with one of the back lights near the bottom of the case.
Anyone know if the unit will attempt to light the back lights if the LCD panel is completely removed? This would be the only way I could see what is really going on.

[airscapes]

Re: Dell W3201c LCD TV

If one lamp is bad, the others will light and then go out when the current monitor circuit sees an imbalance. That gives you a flash of 1 - 3 seconds. Enough time to spot the bad lamp. If none of the lamps light (no flash) then the problem is elsewhere. Is the other TV the same model? either way, $80 is way too much for a broken screen set, especially a Dell. If it is not the same model, the lamps may be different. I found that out the hard way. $20 is fair, $40 if you really want to try and fix this thing.

Yes, TV is the same and Yes, my offer was $10 to start but he thinks it is more valuable since he actually paid full price for it a few years ago! I will do $20 for it if he every posts it again for sale. I am sure he won't get any takers at the $100 he has it list for. Just have to wait and make another offer in a few weeks.
I even offered to sell him my panel for $100 but he didn't want the tv to work, just wanted to make room.. but not letting it go for $20..

[Hobby 1]

Re: Dell W3201c LCD TV

He knows that it is junk and not worth repairing. I have dealth with people who want $500 for their broken screen set because thay paid $1500 and its 2 weeks old and their kid hit it with the wii.... Some will even say that the repair cost is only $150 but they don't want to bother... all BS. Its only worth what someone is willing to pay for it. And in the case of Dell, it is worth even less. If I could give you mine, I would, but it is all messed up and I am too far away.

[airscapes]

Re: Dell W3201c LCD TV

Thanks for the offer! It is funny how I can get attached to junk I get for nothing.. guess I just don't like to be defeated.