Troubleshoot a Dell 2209wa (will not stay on after flickering)

[prdp]

Hello to everyone,

I'd like to know if someone could help me troubleshoot a Dell 2209wa.

First minor issue I had a while ago : http://nsa33.casimages.com/img/2013/...2213214990.jpg

Then the screen started to "flicker", and few days ago I could hear a strange noise on the top right corner.

Now the screen will only stay on for like 2 seconds (with a perfect image) before shutting himself down. (power button's led still blue)

I have read retiredcaps's guide but I couldn't see anything on the screen by shining a flashlight on it. (iphone's flash is enough ?) and I still could hear a strange noise on the board.

I've disassembled it to see if there was any melted capacitor but I couldn't see any. Maybe some "burned" areas on the power board (orange circle) ?

Here are the pictures : http://imgur.com/a/v8etk

How can I troubleshoot this ?

Thanks

PS : I found this service manual if that can help !

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

I'm pretty sure there is an issue with the power board, but I don't know how to find the problem.

Since I don't own an ESR meter, should I replace the capacitors (if yes, which ones?) or can I test the power board with a multimeter ?

Thanks.

[selldoor]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Please can you re post the pictures using manage attachments so they remain to help others.
Not much use saying there is a strange noise when you dont describe it!!
Bang click whistle screech.
I am guessing it may have been a hiss or electrical crackle?

If so Id gueass again that the wiring to the bulbs has given up.

see here
https://www.badcaps.net/forum/showth...highlight=2208

LATE EDIT
Please also post pictures of the Main Board and the Inverter Board

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Thanks for your answer.

I posted the pics in post#2 since I can't edit #1 anymore.

I added the inverter picture. Correct me if I'm wrong but other pictures are the main board (power&logic).

I recorded the sound (.zip attached file) :

@~3s : The "click" is the power button, then you can hear a high pitch hissing sound for 2 seconds until the screen shuts down, then a "buzz" the rest of recording.

If I had to say where it's coming from I'd say from the two components circled blue, but I'm not 100% sure.

[selldoor]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Sorry - gave you a bad link - I think it is nearer to a Dell 2407/8. Try searching for threads for those. The inverter board is different but the tests should be similar.

I will say what I am thinking - In your new member intro you suggest the monitor is nearing its 20000 hours. This along with the flickering often indicates a bulb or the wiring is bad. (only one needs to be bad and they all go out - usually!)
If the hissing IS from the transformers you have marked this is sometimes because they are outputting power that is not being used as the lights are not working.

You can test the output from a power supply board using a multimeter -do any of the sockets have labels such as 24v 12v 5v blon pson etc.
The picture of the inveretr board is not clear enough - can you list the board numbers
for each board.

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

I can't find the thread you are talking about. Can it be a bulb/wiring issue since the screen is able to display the input signal without flickering for 2 seconds ?

Also, on the 3rd picture of post #2, the "burned" diode's bounds is usual ?

PS : Main board and inverter numbers attached.

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Not sure they are the numbers you are looking at though.

Here are the other refs :

Main board = 491881200100h
Inverter = 491882200100h

[elagil]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Please check the connectors on the tubes. I once had a similar problem with that hissing sound. It turned out to be arcing that caused charring of one tube's connector. You might have to clean it.

[selldoor]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Ok Yes those part numbers are better but cant find many pictures and no good ones.

"Can it be a bulb/wiring issue since the screen is able to display the input signal without flickering for 2 seconds ?"

Yes - as the monitor starts up all the lamps try to light. If one bulb or transformer or wire is faulty a protection system kicks in to close it down.
Unfortunately it is not sophisticated enough to just switch off the power
to one bulb/wire/transformer so it shuts it all down.

When there are only 4 bulbs it is not too difficult to locate the problem but
according to the manual there are 6 bulbs but as there are 12 small transformers on the inverter board they may be "u" shaped tubes.

Another difficulty is the main board and the power supply board are in one unit
- it is easier if they are separate.

Are there any labels on the connectors. If not for the pins just like CN1 CN2.
If so what is the one at the top left thw cable that plugs into it appears to have all black and one red wire. Does that go to the inverter board.
Where does the one bottom right go to?
Where does the one in the middle with 8 pins go to - is that the button board?


EDIT Yes as elagil just said the "wires" may not be wires if the bulb connectors just clip straight into the inverter board - take care when cleaning the glass tubes get very brittle.

[elagil]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Yes actually the connectors are made of a special type of rubber which is conductive. This rubber might lose contact over time and cause arcing which leads to audible noise and charring.

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Ok Yes those part numbers are better but cant find many pictures and no good ones.

Do you need better quality pictures of the mainboard ? Anything in particular you want me to focus on ?

I'll try to take better pictures tomorrow with a natural light.

Are there any labels on the connectors. If not for the pins just like CN1 CN2.
If so what is the one at the top left thw cable that plugs into it appears to have all black and one red wire. Does that go to the inverter board.
Where does the one bottom right go to?
Where does the one in the middle with 8 pins go to - is that the button board?

First of all, let me say that it was the first time I disassemble a monitor -this video helped me a lot- and to be honest I have no clear idea how to access the bulbs.

Please check the connectors on the tubes. I once had a similar problem with that hissing sound. It turned out to be arcing that caused charring of one tube's connector. You might have to clean it.

I saw your thread about what may be the same issue. Can you help me find the bulbs ? Do I need to take precautions with this "part" ? What do you mean by "clean it" ?

Thanks guys.

[Per Hansson]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

I saw your post about what may be the same issue. Can you help me find the bulbs ? Do I need to take precautions with this "part" ? What do you mean by "clean it" ?

Thanks guys.

Take a look at the images in this Google search to give you an idea what you are looking for:
https://www.google.se/search?q=ccfl+u-shape+lcd

What commonly happens is that the connector will develop a bad connection and you will have arching going over as the electricity has to "jump" to cover the gap, do a Google search for "tesla coils" if you want to see what it looks like...
The sound in the file you attached earlier sounds very much like this is what is happening...
Warning: CCFL's are driven at high voltage, be careful with them (they are very fragile) and also be careful so you don't electrocute yourself!

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Thanks for your help and explanations Per.

Tomorrow I will try to further disassemble the monitor, but I "kind of" already tried and since I have no idea how to and don't want to damage anything I'd like to know if there's any content that I can look at to help me on this part

[elagil]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Disassembly is not too difficult but you should be careful when handling the tubes. They break easily when you apply too much stress.´

I guess the monitor looks similar to the 2410u inside. Have a look here:
https://www.badcaps.net/forum/showpo...37&postcount=6

That is what the tubes inside might look like.

In order to reach them follow these steps (holds for u2410..):

1.) Take inverter board off (which you might have done already)
2.) Remove signal board on the backside of the panel which has some ribbon cables connected to it
3.) Remove metal frame from the front of the display unit. It holds everything together and might be held in place by some screws
4.) The panel is possibly held down by a piece of tape, remove that and carefully lift out the panel. Do this in a clean environment and place the panel on something smooth (cloth?)
5.) Remove all the light diffusing parts. Be careful not to break them and pay attention not to let dust get in.
6.) there should be the tubes exposed. There now are white bars on the short sides of the backlight assembly which cover the ends of the tubes. Remove the cover that is where the tubes are NOT rounded off. Here are the connectors. This plastic bar could be held in place by screws on the back side.
7.) now you can lift out the contacts of the tubes one by one with something made of plastic. Here you should be very careful. If one contact looks black and charred this may be the issue.

Hope that helps! Unfortunately I have no pictures..

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Ok so I've reached the backlight part and unfortunately wasn't able to spot anything suspicious...

Worse, I think that if it's an inverter/backlight connectivity issue, there's not much I can do due to the design.

See the attached pictures.

Maybe it's an inverter issue ?

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Guys, I think I just spotted something very interesting, and you were right since the beginning

On the 1st pic you can see underneath the connectors's plastic protection.

On the 2nd, the corresponding connector compared to another one.

Problem is, I have to idea how to fix/clean it

[elagil]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Very nice! Just lift out the tube that is affected (lift close to the rubber socket for the least stress) and clean the connector with a cloth and some alcohol or something similar (I used acetone). You can (and should) also lift out the rubber pieces and clean them with water or something that does not harm the material.

I advise you to lift out all of the tubes and briefly check the wire that comes out. If one is already charred, it might cause the monitor to fail again.

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

I'm not gonna lie, i'm a little bit afraid to do that It seems so easy to break !

What tool did you use to lift out the tube ?

Where is the wire you have mentionned ?

Thanks

[elagil]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Actually the tubes are more robust than they seem I used some plastic spudger like this one:

http://www.tekmoz.com/wp-content/upl...dger-tool2.jpg

but it should not matter much what you use. Just do not use something hard like metal. Until you remove the tube, you will not see the wire. It sticks out of the tube at the end.

[prdp]

Re: Troubleshoot a Dell 2209wa (will not stay on after flickering)

Two quick questions before I proceed to the actual fix

1/ I broke one of the plastic "thing" on the backlight part. (See attached file)
Is it ok to fix it with some super glue ?

2/ Living in Paris, there was no way that no dust comes in. What's the best way to clean it ? (I'm worried to use compressed gas because it could spray some "frozen liquid")

Thanks.