IBM 4820 touch screen

**lez** · 09-01-2005, 06:42 PM

O k hours of soldering and here it is.

counting pins on bottom row of silly 14 pin connector working away from vga socket, pin 2 to comport pin 2 , 3 to 3 and 5 to 5. voila.

2 and a half hours of soldering and running the screen finder to get to this, because I was working form pin 14 down........

After 18 month of trying to get a cable etc I have finally cracked it, to find the touch screen is duff! No wonder I was sold it without cables....

Passes all selftests but wont see a touch on the screen.

So if you see or buy one of these, you can now wire it.

At least I can use it as an lcd

**Scouse Monkey** · 09-01-2005, 07:02 PM

try and find a new controller. If it is a 4 wire resistive then get a controller off a xenarc or lilliput or from digitalww

**lez** · 09-03-2005, 07:28 AM

Controller is saying selftest passed, so I am guessing its the screen.

If I plug the touch overlay in wrong it says h/w fail so controller seems ok

I am waiting to try the screen on another known working controller, but its a capacitive controller off a CRT and this screen is a resistive overlay, the controller is microtouch and I think they autodetect. (hopefully)

I also hope to try plugging my controller onto the CRT capacitive pad to see what happens, but its getting to be a wireing jungle having two screens in bits and cables joining all the boards and psu's

**lez** · 09-03-2005, 05:23 PM

well many hours later.........

All working but one corner of the touch overlay is damaged so can only use half the screen........

grrrrrrrrrrrrrrrrrrrrrrrrrrrr...

Time to buy new one!

**lez** · 09-04-2005, 08:22 PM

bwah ha ha ha ha....

Silver conductive paint is my friend!

bought it years ago (about 10!) to fix a keyboard overlay on an amiga a500, but painted it on the glass after being careful to lift one corner of screen and I have a touch screen!

This paint used to be sold to repair rear window heaters on cars but not seen it in years.

Its not perfect, if I draw a square with my finger I get a shape thats like an inverted diamon, IE where the points of the diamond should be the square shrinks in, but its useable.

Its not good enough for windows but now I just need to design big icons to press for my apps and away it goes!

Approaching 2 years and many hours (at least 5 just tonight!) but its paid off, well better than throwing it in the bin!

**Silentbob343** · 09-05-2005, 01:17 AM

ELO Touch Overlays .. 10.5" .. reuseable?

You might want to try and contact AWDNUT factory connectors? Not sure what he can or can not get, but worth a try if you need something.

**Sly1990** · 08-31-2006, 11:36 PM

Did you finished your project? How does it look?
Good work on the SVGA Pinout btw....

I plan to completely redo my dash and center console of my 67 Tbird. So while at it, I could add the 12.1".

I got a 4820 for free with a DFP-to-DVI-I Cable but I had to change a neon inside (took one out of an old 486 laptop display module) and it works perfect now. But I dont know how to make TouchScreen works.

I have the RS485 connector and know the pin configuration, but dont know what to do to with pin 2 and 3.

Pin 1 = 5vdc (for USB)
Pin 2-3 = 2x Data I/O
Pin 4-5 = GND
Pin 6 = 12vdc. (LCD Power Input)

How did you manage to plug the Touch screen?
Did you have to buy/build a converter for it?
Did you plugged USB or Serial?

Thanks

**lez** · 09-01-2006, 03:34 AM

Its serial rs232, noconverter, pins 2/3 to pins 2/3 on the pc 9 pin, oh and a ground from pin 5.

I have removed mine etc as just changed vehicles, I wont be fitting it back in, its too large for a european car/dash.

Max I think I could do would be a 10.2 / 10.4, but will probably buy an 8, when I can afford it.

**Sly1990** · 09-03-2006, 10:22 PM

I tried what you said but I wasnt able to make it detect.

After 1 day trying on a PC with only a HD and a Video Card, I decided to try by USB instead.

I made a cable and used TouchWare SR6 5.xx USB Drivers.

Guess what? Works the 1st time, it detected my Screen, my TouchScreen Module and the monitor internal USB hub. (Happy Me!!!)

Everything works perfect now.
I wish I could put hands on 1 or 2 more freebie like these.

They look to be made to last like every IBM stuff.

They never were the fastest machine, but they alway were the toughest.

**lez** · 09-04-2006, 05:38 AM

If it connected by USB then its NOT a 4820-4ft, a 4ft is serial only, so the wiring posted above is not for you! Please add your connections etc to this thread to help others!

What model is it you have? I guess it is a 4820 but which revision
/model