IGT I-Game Touch Screen Swap

[Justin]

Hello all,

I have an I-Game that the touchscreen was less than functional. Some of the traces came off the glass and such.

I was able to source a replacement and a replacement touch controller because the connector on the old screen was the 8 pin dual row header style connector, and the new one was a DB9.

I swapped over the panel and the controller and I know it's communicating because the calibration utility, which used to have me tap the top right and bottom corner only now has me tap 9 points in a grid on the screen

However, line does not follow my finger correctly towards the lower of the machine. I will link a video

Do I have to change a setting to get this to work?

The only board was labeled Microtouch for IGT v2.9
Not sure what the new one is but the board has a lot more components.

https://drive.google.com/file/d/1s1WVU-PspotJ5UiZefPblG0WrXIr2DOa/view?usp=drivesdk

[Stayouttadabunker]

Obviously, the calibration procedure, before you drew on it, did nothing.
I think there's some IC component on the 3M causing this.
Something on that board is going out of specifications, causing the 3M board to miscalculate where your finger is touching the screen.
As far as I know, there is no real adjustment or "setting" for that - rather, it's more of some electronic component on that microcontroller board, that needs replacement.

OR...


Try to follow my thought here....lol
Your replacement 3M MicroTouch controller that you installed....is made for a square LCD screen...instead of a widescreen?

[Chris-socal]

Hey Guys
I sold that panel to Justin. I pulled it from a 1793, same as Justins. It was allegedly working but got necked. It was passed to me by the previous owner. I will ask the previous owner and see if he remembers the touch working.

I might have another tube that has that same controller so if the general thought is that there is a bad component we should see a improvement or change with a different board.
What confused me is seeing it record his touch pattern at all.I figured if there was a bad component it wouldn’t see his touch.

Mark, do all touch panels talk the same language? There is very little technical information on

Chris

[hotlsot]

I'd like to see a pic of the finger trace test on the monitor. My guess is because it's malfunctioning at the bottom the touch screen is bad, not the controller.

[Stayouttadabunker]

I don't know if the controllers all "talk the same language" but I do know that if there's a micro-scratch on the touchscreen, it severely throws off the touch calculations the 3M board is trying to do and draws erratically.

[Chris-socal]

If you watch his video it acknowledges every touch in 6 places. Doesn’t that set the coordinates?
That touch panel was near perfect, I don’t recall seeing any scratches at all.
One of the wires was smashed between the panel and tube when I removed it but I don’t think it was broken.
I have seen touch panels with far worse scratches and worn spots where someone placed the monitor on the glass onto a surface and they work fine.
But you guys would have more experience than me.

[Chris-socal]

I have another 17” that I use for testing boards. It has a touchscreen on it that I can pull. Our goal is to attempt to determine which component is causing the glitch. Obviously it’s much easier for me to pull just a board.

[Stayouttadabunker]

You're right...swapping parts will find the problem part quickly.

[Justin]

I used doubled sided tape to attach it to the monitor glass. A little bit of the tape is touching the backside of the touchscreen. Could that cause anything?

[Stayouttadabunker]

The problem with double-sided tape is that it's not stiff enough to hold the touchscreen up when the adhesive gets warmed up...the touchscreen will start to slide down...acetate tape is what is needed to support the touchscreen...it's made from some sort of a black material cloth.
I don't think the tape touching the touchscreen would effect anything but you never know unless you take it back off.

[Chris-socal]

Both the screens I pulled had double sided rubber adhesive and were taped. I think Justin told me he used the fabric tape (gaffers tape) in addition to the double sided.

[Stayouttadabunker]

Then the taping is okay..problem is with either the touchscreen itself, or the controller.
I had a touchscreen that drove me nuts one time.
I would be able to touch the "dots" during calibration...but whenever I drew something, one part of the screen would go way off.
I like drawing just a simple "X" across the screen to see which way the controller is sensing my fingertip.
Eventually, I ending up replacing the touchscreen to fix the problem.
I could only see the tiny scratches that some lady did with her diamond ring while holding up the screen with some fluorescent lighting shining from behind it.

[Justin]

So I used some clear double sided tape to attach it to the monitor and sealed the deal with some gaffers tape around the edges. I pulled it off yesterday to look at the smashed wire and some conductor was exposed to I cut out the bad section and soldered and heat shrunk an extension on. I also re did the gaffers and double-sided tape to make sure it didn't touch the screen where there wasn't already tape. It works now !!

[Chris-socal]

I am confident it was the exposed wire.
Great job wrapping this one up. Who knows, maybe someone in the future will have a similar issue and discover an exposed wire for one of the quadrants.

[Stayouttadabunker]

"Exposed wire"....well...we learn something new everyday! haha

[Justin]

Im not too versed on the theory if touch screens, but from what I understand there are two main types, resistive and capacitive. Resistive is mainly reliant on pressure, tapping a spot causes the two layers to collide resulting in a connection with variable resistance depending on the spot. Capacitance, which is what these monitors use, uses the change in capacitance of a human, or conductive material, touching the screen to measure where the touch occured.

My guess is the bare wire was causing the capacitance to change and because it was near the bottom on the screen I think it moved the reference for the lower portion of the screen up wards. Causing my touches to register lower.

This could all be wrong, but that's my guess from a lame man's knowledge point.

[Chris-socal]

You may be a lot of things but a Lame Man is not one of them!
That was well delivered and I thank you for saving me from having to research it!
Your hypothesis makes total sense and until a Digitizer Engineer steps in and says different I believe you.

[Justin]

I would say someone will probably chime in soon, but it seems like not a lot of people jump in anymore. I really hope this hobby doesn't die out for the newer generations.

Seems like its just you and bunker around here and mostly mod's answering questions, it makes me sad