Lilliput touch screen.. manufacturer fault ?

CdRsKuLL · 06-29-2004, 03:18 AM

I have been doing some reading and searching after my touchscreen failed to respond. It seems quite a common fault that the screen stops working after a few months..

symptoms

1st sign is rightside of touchscreen starts becoming inaccurate.
2nd this slowly increases to the rest of the touchscreen.

The drivers i'm using are the same as I've always used and it still shows them installed as usb touchscreen.

As others have stated in the past, the heat causes on the right hand side may have something to do with it. I bought my screen from ebay, and have since looked back at the auction and found that it carried only 30 days warranty. :-(

My questions are ;

If this is such a common fault is it really worth buy the lilliput ?

Do other lcd screen owners have the same faults ?

Pingo1969 · 06-29-2004, 03:22 AM

Quote: Originally Posted by CdRsKuLL

I have been doing some reading and searching after my touchscreen failed to respond. It seems quite a common fault that the screen stops working after a few months..

symptoms

1st sign is rightside of touchscreen starts becoming inaccurate.
2nd this slowly increases to the rest of the touchscreen.

The drivers i'm using are the same as I've always used and it still shows them installed as usb touchscreen.

As others have stated in the past, the heat causes on the right hand side may have something to do with it. I bought my screen from ebay, and have since looked back at the auction and found that it carried only 30 days warranty. :-(

My questions are ;

If this is such a common fault is it really worth buy the lilliput ?

Do other lcd screen owners have the same faults ?

Hi...

I own the same screen, lilliput 7", and mine is starting to do the same...
it is 3 month old, i still have warranty....

BR
Kenneth

storm · 06-29-2004, 03:39 AM

Hmm this is really strange!!!
I have the same problem. The right side of the touchscreen starts to be bad.
BUT!!! I use Pivot Pro, that rotates the screen 180 deg!
That's very strange, it would have been the leftside of my screen that was wrong. That indicates that there's something wrong with the drivers not the hardware. Or am I wrong?

phc · 07-04-2004, 01:40 AM

My Lilliput TS went funky on the right side, but vertically its fine.

Today I pulled it out today and decided to compare it to a new one I had.

By measuring the resistance on the 4 wires of the touchscreen, I found this:

Pins 1 & 3 had ~350 ohms
Pins 2 & 4 had ~ 4.5k ohms

Looking at the new one:
Pins 1 & 3 had ~350 ohms (vertical)
Pins 2 & 4 had ~ 700 ohms (horizontal)

There is no resistance between horizontal and vertical pins.

So, 350 ohms is a good measurement for the vertical resistance and 700 ohms is good for the horizontal (2x the resistance because its 2 times longer).

Then I tried to see if I could repair it, so I pulled off the flex cable from the touchscreen, I actually just peeled it back to expose the connection - which breaks the connection. I measured the same resistance, so its not a connection issue - it has to be a touchscreen issue.

I also changed the USB touchscreen board out, same results.

Once the touchsreen goes bad, I don't see any easy way to repair it.

But, I did do some experimentation with the flex connector as the new TS was intermittently working. So I pulled back on the flex connector and dabbed some conductive paint in there - it worked great.

So for you who have touchscreens that do not respond at all, this may be a quick fix. I went to Kragen auto and got a Permatex window defogger/defroster repair kit for $10. Its basically nail polish with very fine copper dust. I dabbed a very small amount under the flex and it fixed the intermittent issue.

danilom · 07-05-2004, 03:59 AM

Here are my 2 cents

As far as i know, Lils use resistive touchscreens. As i see it, either from heat or from regular use. the resistance goes up making it harder for the controler to figure out what is a touch and what not. I am not sure but on which side are the conectors for the TS? My guess is ther are on the right. This would not be the problem with the capacitance TS, but those are more expensive, and then you have full glass touch screens which are the best. These are the cheepest out there and this is probably their normal operational ware. Plus being enclosed in the dash with all that heat can't be good either. I plan to put a silent fan behind my LCD to cool it.

mp3oplecarrier · 07-05-2004, 04:15 AM

Quote: Originally Posted by phc

Once the touchsreen goes bad, I don't see any easy way to repair it.

But, I did do some experimentation with the flex connector as the new TS was intermittently working. So I pulled back on the flex connector and dabbed some conductive paint in there - it worked great.

So for you who have touchscreens that do not respond at all, this may be a quick fix. I went to Kragen auto and got a Permatex window defogger/defroster repair kit for $10. Its basically nail polish with very fine copper dust. I dabbed a very small amount under the flex and it fixed the intermittent issue.

I had a problem with my touchscreen not working at all from new (no worthwhile returns policy, ebay supplier) and took it apart to see if I could fix anything, where did you put the conductive paint, on the actual TS? Do you have any pics?

PS with regard to suppliers for the lilliput, I notice that in the UK, www.mini-itx.com now stock these, and as a UK supplier with a real address we may get some better support!

Steve

Confused · 07-05-2004, 04:31 AM

LinITX.com, which is also in the UK, and who both myself and my boss have had good experiences with, have Gain (Xenarc) 7" screens, and the Lilliput 8" screen.

I can seriously recommend you spend the extra £90 on a Gain screen, from experience of both products (the new Gain screens are brighter, easier to read in the sunlight, less glare, better touchscreen and much better build quality), my mate who has a Lilliput is now saving up to get a Gain screen after seeing mine.

Garry

phc · 07-05-2004, 03:21 PM

Quote: Originally Posted by mp3oplecarrier

I had a problem with my touchscreen not working at all from new (no worthwhile returns policy, ebay supplier) and took it apart to see if I could fix anything, where did you put the conductive paint, on the actual TS? Do you have any pics?

PS with regard to suppliers for the lilliput, I notice that in the UK, www.mini-itx.com now stock these, and as a UK supplier with a real address we may get some better support!

Steve

I peeled up the flex connector from the glass (the brown flat cable) and exposed the contacts on the glass. I put a tiny amount on the contacts, careful not to short the connections.

I'll put up photos later tonight.

phc · 07-06-2004, 01:25 AM

Quote: Originally Posted by phc

I peeled up the flex connector from the glass (the brown flat cable) and exposed the contacts on the glass. I put a tiny amount on the contacts, careful not to short the connections.

I'll put up photos later tonight.

Added Photo

The defroster repair kit is easily available, but a better choice would be conductive epoxy- 2 part epoxy with silver dust, harder to find.