Samsung 216BW - Partialy scrambled screen image

[DKuhrt]

I have a Samsung 216BW monitor that I got along with some other monitors needing repair. This monitor powers up, but the bottom two-thirds of the screen is completely scrambled and slowly goes dark. The top one-third of the screen displays perfectly. I dis-assembled the monitor. The power supply board looks fine, no signs of bad capacitors. The logic/processor board appears to have had all its original capacitors replaced by someone with mediocre soldering skills.

My question is. . . Based on the description of the screen display I provided, does this seem like this is an effect of a poor capacitor replacement job? or is it an indication of a deeper problem? (such as a processor chip, etc.)

Thanks for any and all guidance.

DKuhrt

[CCL_Tech]

Hello and welcome to our forums,

Well the controller card does make everything work. If the 'repair person' did a bad job on the capacitor replacements and bridged any solder joints then it could very well cause the issues you are describing. The first thing to check is the solder on the replaced parts. Be sure there is not any where it should not be. You may need to remove the capacitors fully and then put them back in. The next thing to check it the connections from the controller board to the display panel. Be sure they are well seated on both ends and that the cable is not damaged. Check those things and let us know how that goes, we can go from there.

[DKuhrt]

Well, I removed, checked for solder bridging, and re-solder all the capacitors one-by-one. I did find one capacitor that was installed backward regarding the indicated polarity, but no other problems. After re-assembling the monitor, there was no improvement.

I've uploaded a picture of the screen.



Any guidance or suggestions on what to try next would be appreciated.

Thanks, DKuhrt

[CCL_Tech]

Electrolytic capacitors really do not like to be installed in reverse you might want to get a replacement part for that one and replace the cap. Your picture looks like the frame buffer memory is not initializing correctly. Look on the flat pack IC chips for pins or legs that might be bend and shorting to each other. By the way what is the manufacturer date on the back of the monitor?

[DKuhrt]

I carefully examined the "flat package" and saw no signs of mis-aligned or damaged pins. I also checked the cable for continuity on each conductor - no problems there. Here are some pictures:

Processor Board

P1020404.JPG (163.35 KiB) Viewed 325 times

Processor board "flat pack"

P1020405.JPG (145.85 KiB) Viewed 325 times

Processor board model #

P1020407.JPG (116.8 KiB) Viewed 325 times

The date of manufacture is June 2007.

[DKuhrt]

Ok, here's another update.

I got hold of a Samsung 206BW monitor. Pretty nearly identical, just 1 inch smaller. All of the cabling and connectors are identical between the two monitors, so I swapped the entire electronics box (power supply and processor board) from the 206BW to my ailing 216BW. The 216BW continued to display exactly the same defective, scrambled display. So this rules out problems with the power and the processor boards. That leaves the LCD control board (mounted on the top, back of the LCD panel) and the LCD panel itself.

Well, further playing with it powered-up, I find that squeezing the LCD panel in a couple of spots on the edges results in restoring a normal screen image. So it is indeed the LCD panel itself (the thin film ribbon cable connections on the panel) that is having connection problems. :-(

Thanks for all the assistance. It was indeed a learning experience.

DKuhrt