vne147
Member
Hello everyone. I’m working on something and have hit a snag and could use your help to resolve it. I’m trying to help a friend with a project where he is modifying an LCD monitor and a graphics tablet for a PC. The end result of the modification is that he will be able to draw driectly onto the monitor instead of having to draw onto the graphics tablet. I’m pretty sure the tutorial he is following is here:
**broken link removed**
As part of the modification, he has taken apart the LCD monitor. Inside the monitor is of course the LCD itself and associated lighting but also inside are two PCBs connected to the back shell. One PCB is the power supply/inverter board and the other one has the LCD driver ICs.
The power supply/inverter board connects to the CFL lights on the edges of the LCD through a pair of wires. There are two edge lights so 4 wires total.
The other board connects to the LCD through a 34 pin data cable. Here is a picture of the cable:
https://www.electro-tech-online.com/attachments/imag0068-jpg.34858/
Since this monitor was never intended to be taken apart, the cables inside (data cable, CFL cables) are much too short for his purposes so he asked me to lengthen themfrom about 6 inches to about 5 feet.
I was able to make an extention cable for the data cable using some 2mm IDC connectors, a 2mm header and some 1mm pitch ribbon cable. I did not put any kind of suppresor around the cable. Should I have? For the lights, I just spliced and soldered extra wire to the CFL wires to lengthen them. Sounds simple right? Well, neither one of the “extension” cables works as expected.
First off, the data cable does work well enough to display an image but it is not the complete image. It is distorted and there are some horizontal lines that obscure the image. If I had to guess I’d say it seems like there is some interfence or problem with the clock signal that’s causing certain pixels to show up in the wrong place on the monitor.
Second, the CFL lights don’t light up all the way. It appears they only light up about halfway down the length of the tube. The half that is lit is still dim compared to what it should be and the other half isn’t lit at all. I would have expected some line loss with the extra cable length but this seems excessive.
My questions:
What have I neglected to consider?
Short of returning the cables to their original lengths what should I do to make the extension cable work both the CFL and data cables?
Please let me know if any of my descriptions are unclear or if you need some more information. Any insight or ideas would be much appreciated. Thanks in advance.
**broken link removed**
As part of the modification, he has taken apart the LCD monitor. Inside the monitor is of course the LCD itself and associated lighting but also inside are two PCBs connected to the back shell. One PCB is the power supply/inverter board and the other one has the LCD driver ICs.
The power supply/inverter board connects to the CFL lights on the edges of the LCD through a pair of wires. There are two edge lights so 4 wires total.
The other board connects to the LCD through a 34 pin data cable. Here is a picture of the cable:
https://www.electro-tech-online.com/attachments/imag0068-jpg.34858/
Since this monitor was never intended to be taken apart, the cables inside (data cable, CFL cables) are much too short for his purposes so he asked me to lengthen themfrom about 6 inches to about 5 feet.
I was able to make an extention cable for the data cable using some 2mm IDC connectors, a 2mm header and some 1mm pitch ribbon cable. I did not put any kind of suppresor around the cable. Should I have? For the lights, I just spliced and soldered extra wire to the CFL wires to lengthen them. Sounds simple right? Well, neither one of the “extension” cables works as expected.
First off, the data cable does work well enough to display an image but it is not the complete image. It is distorted and there are some horizontal lines that obscure the image. If I had to guess I’d say it seems like there is some interfence or problem with the clock signal that’s causing certain pixels to show up in the wrong place on the monitor.
Second, the CFL lights don’t light up all the way. It appears they only light up about halfway down the length of the tube. The half that is lit is still dim compared to what it should be and the other half isn’t lit at all. I would have expected some line loss with the extra cable length but this seems excessive.
My questions:
What have I neglected to consider?
Short of returning the cables to their original lengths what should I do to make the extension cable work both the CFL and data cables?
Please let me know if any of my descriptions are unclear or if you need some more information. Any insight or ideas would be much appreciated. Thanks in advance.