Dell W3201c LCD TV

[Hobby 1]

Re: Dell W3201c LCD TV

Get use to it. Most of this stuff will be impossible to fix 5 years from now. No parts, obsolete electronics, etc.

[PlainBill]

Re: Dell W3201c LCD TV

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.

That is probably the 'Backlight On' signal. You are right, it's a mechanical problem, probably a bad solder joint. The signal originates on the main board.

Proper troubleshooting technique for these problems is to use a nonconductive device and gently tap at various points until you reach a spot where the littlest tap will cause it to pop in and out. Then it's time to resolder everything in the area.

PlainBill

[airscapes]

Re: Dell W3201c LCD TV

I found this problem! Doubt it is the problem that I had to start, that one (shut down when it wants) is probably still there.
The back light not working and then flashing when the case was bump was caused by me.
I pulled off the DC-DC board to see if I could check the capacitors and when doing so, I pulled the board side of the connector I have circled up off the pins just enough so there was a bad connection.

To find this, I removed the LCD panel and hooked everything up with the case holding the backlight and inverter face down on the table propped up a bit and the rest of the case on the stand. I could see the bottom 4 tubes not lighting proper so I check all the connections with a meter (resistance of solder joint) with power removed. Not finding anything I powered it up and banged on the case holding the inverter and tubes, and it did not light. Then I tapped the other case that was no longer attached and the lights went on. After that it saw a tapping game till I figure out it was that connector.
Once the board side was pushed down flush the connector made contact and everything works fine.
Total reassemble and will set it in place and use it to see if it will be stable and reliable .. you and I know it won't.

One thing I did notice. With the metal cover off, the tv does not seem to shut off, with it on, it does. This happens in just a few minutes so not really heat related. While putting it back together, I notice that the cover does not fit as well I I would like, and when putting all the screws in that hold the input/output connectors it looks as if some stress is put on the main board.. That is where I will look next if it is still shutting down..

[airscapes]

Re: Dell W3201c LCD TV

UG.. yep shut off again.. So.. I have created 2 new problems, and fixed both of those and still have the original and no closer to pin pointing what is causing it.

[airscapes]

Re: Dell W3201c LCD TV

I am getting closer! I had figured the No start at all condition I had a week ago was not the same as the shut off, they are the same.

If I start the TV cold it run for a 5-10 minutes and shut off. The 5v light is on the main board is on and the power button is lit blue.
Press power button 2 times slowly and the blue light goes out. Press it again and the other 5v and 12v leds blink on for a second and go out. If I wait long enough the TV will start and run for a while and shut off again. It seemed if I kept this up it would then stay on all day.

I took off the back and metal cover again and let it sit. Started it and waited for the shut down. Once it happened, I heated the power supply with a hair dryer right over the large round transformer on the secondary side for about 45-60 seconds. The TV will start and run all day without a problem once it is hot enough.

Now, what would cause this? I am thinking a winding in the transformer rather than a solder joint... any thoughts?

In the mean time power supply coming off yet again and I will solder EVERY connections in the center area of the board regardless of how it looks!

[alexanna]

Re: Dell W3201c LCD TV

If you haven’t already, remove the transformer clean and inspect all the pins. You could have a poor connection where one of the wires is attached to the pins.
Al

[airscapes]

Re: Dell W3201c LCD TV

Well I think I have beaten it at last!
I took the PS off again and reheated adding a little solder to EVERY connection that was not a surface mounted part. I also replaced the fuse on the board (sorted it out with the metal cover on the hair dryer by accident) Don't think the fuse had anything to do with it since it was not near the hot air from the dryer.
As of now, the unit has not shut off, and I even put it all back together the other day.
I did not put the screws in that secure all the I/O connectors since I am not going to be plugging and unplugging things and I didn't want to add any stress to to the main board. I did loosen the main board and the PS prior to installing the metal cover and pushed both boards up towards the top as far as they would go and then tightened the mounting screws. This allowed the metal cover to line up with it's screw holes exactly without putting pressure on either board. I get my wall mount next week .. crossing my fingers it stays fixed..

If you found this thread because your are searching for a cure.. I am sorry I do not know which connection was the issue. If you have the same problem as I did.. shuts off and will then work later on.. remove the back plastic cover, metal cover, reinstall the stand. Start it up and wait for it to power off. Try and power it back on, if you see the 2 green leds on the main board blink on and off when you attempt to power it on, get a hair dryer and heat the PS in the center for 60 seconds or so and see if it does not then start.
If so it is your PS so don't touch anything else, you will just make more problems that will confuse the real issues.
Good luck!!
Any questions about hacking the soundboard feel free to email me.

[teg01985]

Re: Dell W3201c LCD TV

Hello can you please explain what picture is what plus i dont know if you would know but i have a w3201c tv and the blue light comes on but the screen stays black i could hear it when it turns on. its just the screen and the sound doesnt turn on. i found the tv in the dumpster so i figure ill take it and see if i could fix it also to pass time. thank you.