Samsung 2443bwt buzzing and low bightness

[Sarveok]

First off, I have almost no experience with the electric part of computers. I am a programmer with a masters in AI but have never had the chance to work on the electronics directly.

So my company recently tossed a few monitors and in the process I picked up a Samsung 2443bwt. Their reason for getting rid of this is because it is dim as well as making a buzz when turned on. After a few seconds, the monitor will just shut off.

Regarding the buzz, when you lower the brightness, the buzz goes down. When you approach 0 brightness, the monitor will shut down. The buzz is coming from the upper corner where the LCDs make one of the two connections to the Main board. When it is on, the wires going to that region are vibrating and when you move the wires, the buzz and vibration change.

Here is are two images to show where the noise and vibration are occurring.



Looking through the main board as well as the secondary board, none of the capacitors look expanded. Of course, I am not a professional on this.

Here are a number of other pictures from the main board:







And here are 2 images of the secondary board:




I know many of these pics may be pointless, but I took a number of them at differing angles to let you see what is in there.

Thank you very much for any responses I get from this.

Lucas

[retiredcaps]

Re: Samsung 2443bwt buzzing and low bightness

I know many of these pics may be pointless, but I took a number of them at differing angles to let you see what is in there.

Please edit your original message so that pictures/images are not inline. Upload here using the manage attachments after reading (but not inline because they slowdown the loading of pages)

https://www.badcaps.net/forum/showthread.php?t=1868

[retiredcaps]

Re: Samsung 2443bwt buzzing and low bightness

Regarding the buzz, when you lower the brightness, the buzz goes down. When you approach 0 brightness, the monitor will shut down. The buzz is coming from the upper corner where the LCDs make one of the two connections to the Main board. When it is on, the wires going to that region are vibrating and when you move the wires, the buzz and vibration change.

This may be arcing in the ccfl housing as the ccfls age they draw more power. The wiring could be breaking down or the solder may be bad. See this thread

https://www.badcaps.net/forum/showth...ghlight=arcing

[Sarveok]

Re: Samsung 2443bwt buzzing and low bightness

So i dove into this a little further and found that one of the 2 top lights was not turning on.

Once again i am ignorant and am assuming that the bulb is bad. But the whole things turns off after a few seconds. With this in mind, maybe there is something else that could be an issue.

Also, there is a smell in that bad corner when it is on. burning plastic.

Any ideas?

[retiredcaps]

Re: Samsung 2443bwt buzzing and low bightness

So i dove into this a little further and found that one of the 2 top lights was not turning on.

Once again i am ignorant and am assuming that the bulb is bad. But the whole things turns off after a few seconds. With this in mind, maybe there is something else that could be an issue.

The way most LCDs work is that the inverter chip checks to make sure that all ccfls are working with specifications. If even one is out of spec, it shuts down them all to protect the system. This is the 2 seconds to black.

Because of this "protection" system, you will not get a "dim" display where the top 2 lights are off and everything else is on. It is "all or nothing".

PlainBill describes 2 seconds to black best ...

https://www.badcaps.net/forum/showpos...2&postcount=18

https://www.badcaps.net/forum/showpos...8&postcount=64

[Sarveok]

Re: Samsung 2443bwt buzzing and low bightness

Ok, for some reason, I didn't think of this before. I switched the sockets for the upper and lower light and when powered on the same upper bulb was not lit. I assume that this means that the bulb has an issue.

If so, samsung says I have to buy 200$ replacement panel. Anywhere out there for me to be able to buy just a new bulb?

[retiredcaps]

Re: Samsung 2443bwt buzzing and low bightness

If so, samsung says I have to buy 200$ replacement panel. Anywhere out there for me to be able to buy just a new bulb?

If you are certain it is the ccfl tubes, there are a number of options.

1) http://ccfldirect.com/

2) http://ccflwarehouse.com/

3) ebay

http://shop.ebay.com/?_from=R40&_trk...All-Categories

Taking it apart and replacing the ccfl tubes is a very fragile and delicate operation.

[PlainBill]

Re: Samsung 2443bwt buzzing and low bightness

Taking the panel apart is certainly the next step. The buzzing sound and the smell of burning plastic could indicate a broken wire at the point where it attaches to the tube. It may be possible to repair it.

As retiredcaps indicates, a very delicate operation.

PlainBill

[delaware74b]

Re: Samsung 2443bwt buzzing and low bightness

Look at the upper left corner of the second photo on original post. It looks like the CCFL leads near the corner are burned.

[shovenose]

Re: Samsung 2443bwt buzzing and low bightness

you could look on ebay for a new panel, install it, try to fix the old one, and if you succeed sell the one you fixed on ebay?

[lucky13]

Re: Samsung 2443bwt buzzing and low bightness

Sarveok,

Changing the CCFL lamps inside a panel is very risky. You will find they use tapes that are hard to remove. I have personally cracked a few.

Since your panel is displaying a pciture (when light is provided), you can try to get those CCFL for computer case mod. get one that is like 22" long. Use it to bypass the bad one inside and the inverter will not shut off. A 24" might fit but you likely will have to put it at an angle so you can close the back.

I once left it taped to the back of the panel and so the LCD has only 3 lamps inside. It was bright enough to use. The 4th lamp illuminates the inside of the monitor for "mood" lighting.... Just a wild suggestion (this is not a fix but a bypass) so don't flame me guys