Yet Another CF-18 Touchscreen Problem

I acquired a well used unit without stylus or power supply, I did get to see it run before the battery died. I was able to see it functioned ok, the touch screen worked with a PDA stylus and then I lost power... I cleaned it all up nice and pretty, because it looked like it had not seen use in a while. And I waited...

When the replacement power supply showed up (after waiting an eternity), I was quick to charge this baby up to clean it out and start fresh. But as I used it a little to see what was still left on the machine by the previous owner, I noticed the touch screen didn't respond properly. It was like it was dead. Touch pad worked ok.

I remembered reading about the ribbon cable loosing connection, so I quickly disassembled the unit to check. After seating the cable it appeared to help, as I was actually able to touch the crosses in the calibration. But it gave an error at the end and did not work after all.

I noticed that with each time I touched the screen the cursor would jump to the bottom right corner, you could move it back with the touch pad. You could repeat as many time as you liked, with same results.

Again, memory served me once more about using paper folded to remove lodged dust/dirt/crud from around the bezel and around the touch pad. It was all in vain, nothing helped same results.

I decided it must be a software problem, mostly because I did not know the past history of the machine. I fumbled with a USB stick till I got XP SP2 loaded back in with the drivers I download for a MK4 in the proper sequence mentioned here. No change...

I am out of ideas, beginning to think TS is bad... Not sure how/why it went that way, but cannot see anything else being an issue. Throughout the whole ordeal the touch pad has work perfectly and the touch screen not. Well except the first time out before the battery died...

Model # CF-18KHHZBE it has WWAN installed with SIM card, 802 and no GPS/Bluetooth.

Any suggestions??

 

Our CF-18's do not work properly with any stylus that is not a TB stylus. I believe this is due to the type of touchscreen. There is a magnet or something in the tip of the pen, and the CF-18 is specifically designed to use it. I forget all the techy details, i haven't had my coffee yet and before coffee i can barely pronounce Linux.

 

The above post is not at all accurate. There is a difference between the digitizer and the touchscreen. ANYTHING can be used on a working touchscreen.... A stick, toothpick, curling iron... Anything you wnt to poke at it. The digitizer models require a special digitizer stylus. I think that is where the prior post is confused.

As to the dancing touchscreen. If you read some of the stickies you will find your answer. t could be one of several things. Driver issues if the OS was loaded and driver not installed ..... It could be crud that has built up between the touchscreen and the inside of the surrounding bezel. This can happen when you "clean it up".... You can try scraps of plastic about the thickness of a plastic soda bottle to try to fish it out. It could also be something similar with the touchpad. Or.... You could just have a bad touchscreen....

Good luck and post back...

 

Incorrect, im saying exactly what you are saying. You are working on the impression that he has a touchscreen in the true sense, where i believe he has a digitizer touchscreen. He indicated that the computer did not come with a stylus, which would be irellevant if he had a standard touchscreen.

I explained that his issue may be due to the lack of the TB stylus, because it is a digitizer system.

 

The O/P did, (what we like to see) post his model number

Toughbook, Myself and a few others here can just take a glance at the number and tell that its a touchscreen

For reference

http://www.config.toughbook.com/

Alex

 

ahh, i missed that. At least i wasnt confused on the facts, just the type of TB he had

 

I'd suggest more work getting crud out from around both the touchscreen and the touchpad. I had a similar issue on mine, and it turned out to be crud around the touchpad that was causing the touchscreen to act weird

nine

 

I have been digging around the edge for while... Does not seem to improve at all.

I re-installed and started fresh, following steps outlined here for drivers and apps... Even tried to uninstall driver and install again.

I cannot see anything stuck around around the bezel. I have a hard time believing that a touch screen might go bad in the manner this one did. If I could find a replacement gasket I might try removing to inspect closer. I'd just cut the gasket with a razor, then remove what is left once I have panel out.

The cursor always goes to the point on the screen...?

 

I had a similar problem a while ago after using my aussi CF-18 extensively in tablet mode. I ended up buying a replacement touchscreen for the TB.

My theory is that the mechanical flexibility and the needed space between the two layers of the touchscreen has worn out at the place where the cursor is stuck.

Things improved a little by leaving the screen untouched for a couple of weeks. Bending the whole screen assembly with a lot of force (and madness ) did also solve the problem temporarily. But at the end I got a digitizer version....and I love it (especially with 7)! Note; this is just theoretic and its not backed by any facts....

 

I find it odd that any amount of pressure sends it to them same location, just below the clock in the bottom corner.

Any location touched does the same...

 

My problem spot was near the middle of the screen. Big change that there is something between the bezel and the screen if the spot is near the bezel.

I don't think breaking the seal is a good idea. Its difficult to get watertight again and the part is not really easy to get.

 

not sure on what the problem could be excatly,
however i have experianced briefly a issue with the touchscreen "locking" the cursor in one place.
I would touch elsewhere and it would always jump back to the static location where it seemed to have locked.

After some poking and fiddling i discovered that by double tapping the static location, would free the cursor, this happened a few times when i first recieved my CF-18.

after updating some drivers and getting the hotkeys fixed (tho i was sure they were all irrelevent to the touchscreen) I have yet to have this problem again.

Prehaps just a ghost in the machine but who knows might be of some help.

 

I have tried a number of times so far, I cannot see anything obvious in the gasket around the edge. I have tried paper and thin plastic, it seems like things are coming out but I think it is just bits of foam.

Everything worked ok before I cleaned the unit with a toothbrush (was quite dirty) and cloth. I know the touchscreen worked properly, as I did the calibration to check it. I drew a nice picture in the test mode...

It does not matter where I touch the screen the cursor always jumps to the same spot. I would guess the location would indicate where the problem is, but I find nothing?

I really do not understand why touching anywhere would have the cursor go to the same spot, if there is something touching the screen. I can understand it confusing the panel, but not necessarily jumping to the same point.

I will continue to try...

 

Anyone have a service manual for this unit?

 

Did some more digging around the bezel... Seems to have helped a little, as I can now move cursor up and down on right hand side of the screen. Still stuck to right, but progress I suppose...

I am suspecting that the crap is between the touchscreen and the gasket glue. Not between the bezel and screen.

 

Ok, I took it one step further, I removed the touchscreen (carefully!) to test without the gasket... Same results...

Guess it must be the TS or TS PCB..

It seems like it might be the paper connector causing it, as sometimes I get no response after putting it together. Then I take it apart and check connections, then it works (partially, same as before).

 

That problem is the same on cf-29 as we discussed before. The coz is the very thin circuit line along it edges or maybe on the cable ribbon itself. Overtime it burn out. Phsyco...a member here bought a defogging repair kit, its like a pen to repair those area that burn or crack. But he never been come back to see how its goin.


teo

 

I am thinking the same.

I am just not too sure how to locate where the problem lies?

I would assume that because I can move up and down on the right edge, that the Y portion is working and that I need to look at the other. How can I figure out which pair is for the horizontal axis (X)?

 

I took it out again...

Tried the trick of using heat from hair dryer to heat the glue around the panel. I had one pair y-axis that gave me readings of about 350 ohm and the other pair infinite. Heating the edge for x-axis did not seem to help too much, then it started to work. I tried applying the heat on the ribbon that joins the cardboard (?) and testing again... Bingo! I finally got a reading for the x-axis. When I tried it again it worked once again!

I put everything together and all is well so far... Not sure how long it will last?

I will post the results after I have used it for a while.

 

It means that the joint between the cable ribbbon and the thin circuit line that goes to the glass panel are running open(Zeta). if you could place a rubber piece between the lid cover and LCD to make it tight enough it could solve the problem in the long run.

ohlip

 

The touchscreen reverted back to no x-axis... Lasted two days, going to open it again to try a more permanent fix now.

Was good while it lasted...