GO 730 ghost tapping issues

[canderson]

...went against what's usualy advised here...

We don't advise against screen protectors, rjsa. I run one on each of my TT units. We only suggest that it is possible that a screen protector that has begun to shrink (the good ones don't do that) can cause pressure on the screen and create the phantom presses. So for those that are reporting this problem and cannot resolve it through normal bezel means, we suggest that they remove any protector they might have installed to see if that changes the behavior.

 

[rjsa]

...went against what's usualy advised here...

We don't advise against screen protectors, rjsa. I run one on each of my TT units. We only suggest that it is possible that a screen protector that has begun to shrink (the good ones don't do that) can cause pressure on the screen and create the phantom presses. So for those that are reporting this problem and cannot resolve it through normal bezel means, we suggest that they remove any protector they might have installed to see if that changes the behavior.

Don't get me wrong, I was not directing my comment to anyone . I had been struggling with this for a while, and every thread I found put as item #1 to fix this problem to remove the protector.

In this specific case (which I also see) where the screen will keep jumping when clean and touched by nothing, it seems to me that the screen is over sensitive and a protector bleeding out from the sides will shield it.

 

[canderson]

Most often here, our threads have FIRST suggested working a thin card around the inside edges to see if there is any debris there. Second, we have asked about possible screen protector issues. More recently (the last year or so) we've begun to focus specifically on gasket/bezel issues.

I just want other readers to know that we do NOT suggest people avoid screen protectors.

 

[rjsa]

That's an interesting solution... Normally we specifically say to REMOVE any screen protectors, as they are known to cause "phantom presses" as they get older.

This one got me confused then, sorry.

 

[canderson]

What Andy is saying is that we don't recommend adding them to see if it solves a problem, only to remove them to see if it solves a problem.

Your addition to of a screen protector wasn't a direct part of the resolution of your phantom key issue (your unit would have ceased to misbehave without it), but depending upon how you installed it, may be protecting some surfaces that were previously being protected by the bezel.

 

[rjsa]

What Andy is saying is that we don't recommend adding them to see if it solves a problem, only to remove them to see if it solves a problem.

Your addition to of a screen protector wasn't a direct part of the resolution of your phantom key issue (your unit would have ceased to misbehave without it), but depending upon how you installed it, may be protecting some surfaces that were previously being protected by the bezel.

Sorry but I'll disagree, I know how close I was from ditching the little thing, how many silly fixes to the problem I tried, how many times I opened and closed it before getting it stable after doing this.

Wrong and patronizing, well done.

 

[dhn]

Wrong and patronizing, well done.

Glad things are working for you but with the attitude you show, well, you will understand if others don't exactly rush to your assistance if you post other problems with your unit.

 

[rjsa]

Never mind... over & out.

 

[Andy_P]

That's an interesting solution... Normally we specifically say to REMOVE any screen protectors, as they are known to cause "phantom presses" as they get older.

This one got me confused then, sorry.

Wrong and patronizing, well done.

Jeez, what is your problem?

How was my reply confusing?

Split it into parts:

"That's an interesting solution....." Yes, it's interesting. That's the very first time I've heard that work.

"Normally we specifically say to REMOVE any screen protectors...." Yes that's exactly what we suggest WHEN people have problems, because in the majority of cases that was the cause (before this latest warped bezel issue).

"...as they are known to cause "phantom presses" as they get older." Again,through experience we found some screen protectors that worked fine at first, began to cause problems later.

If you've found a different solution, GREAT.
But canderson was only explaining why we say what we say, after YOU said it was confusing. Why then insult him?

 

[canderson]

I'm still unconvinced that adding a screen protector was necessary at all. There is no reason that I can conceive that this would improve anything. A good quality one will not hurt, but no cause for improvement.

I'd be very interested in hearing whether the OP actually removed and dealt with the bezel and tested in that state before the application of the protector. We never got a blow by blow explanation of where the protector came from or why it was applied. One would assume to deal with fact that the edge protection had been removed?

 

[rjsa]

Jeez, what is your problem?

How was my reply confusing?

...

Your post was clear enough, I'm sorry for dragging you into this with my poor attempt at irony.

 

[rjsa]

I'm still unconvinced that adding a screen protector was necessary at all. There is no reason that I can conceive that this would improve anything. A good quality one will not hurt, but no cause for improvement.

I'd be very interested in hearing whether the OP actually removed and dealt with the bezel and tested in that state before the application of the protector. We never got a blow by blow explanation of where the protector came from or why it was applied. One would assume to deal with fact that the edge protection had been removed?

I'll try to give a complete step by step on this, not being stingy with my words as usual what tends to add confusion to the process:

I got my unit (a go 720) from my wife as a gift.

First day out in the street, after some 20 minutes it started shifting around by itself. Even before I started searching I got under the impression that it started failing when the sun hit the screen (Later on I went to discover that some people link the failure to temperature cycling).

Called TomTom Brazil and was told since the unit was purchased in the U.S. I was on my own. I do buy many things abroad and aways get service, even if it's not free. This TomTom device will be my only one, never again.

Then I did my first google searches to find the card under the bezel trick. I'm not sure it worked at all. I'd stop and dig into the bezel, then drive for another 10 minutes and the problem would be back. Those where test runs, I really didn't need the navigator, so I just shut it off.

After a week or so my wife came with the screen protectors - she is addicted to them - and gave them to me. These where protectors designed to fit the screen and applied without disassembly. The unit had been stored for that period. After installing the protector I went testing it again and it worked fine.

It worked fine for a month or so until I put it in the floor by the front passenger seat prior to parking on the street. I stayed there among my mess for about another week until I noticed it and picked it up.

This time it was so messed up it wouldn't even go past "I Agree" after boot. I just couldn't tap anything.

I then went desperate measures and opened the unit for the first time, removed the protector and tested it unassembled. It worked. I then added the second properly fit protector with the unit still opened. It was a bit misaligned, covering some of the grey bezel in the bottom part of the screen. Reassembled the unit and it worked just fine for another couple of months.

In the mean time I used it in Brazil and took it to Los Angeles, using it for 10 days non stop there without a single glitch. By this time I was already packing my torx kit just in case.

Back to Brazil, another couple of problem free months and I went to Italy. Picked the rental in Milan and after 2 hours driving it started pointing me to the carabineri when I was about to leave the main road towards Lucca. Me and my wife got pretty nervous at the car. Stopped on the road side, tried the card and it would go for another 10 minutes and fail again. I keep the volume down but my wife noticed despite the crazy screen the verbal instructions where still good. Parked again, raised the volume and went on. We did manage to get the mountain road way right by ear and got to the hotel. We where pretty worn out after an overnight flight in coach and this struggle with the 720.

My wife was devastated since it was I gift, and still pretty new. Wasn't for that I'd have ditched it and got a new Garmin. The 720 itself wasn't worth the stomach pains.

Next morning I opened and cleaned it, it worked for a while and started misbehaving again. We where able to go places on the voice guidance, but the 720 was spoiling the trip. I opened it again, removed the protector and cleaned the screen. It was jumping around with the bezel and rubber gasket off, clean - nothing touching it.

At this point I figured either the touch screen was shorted or something was exposed giving excessive sensitivity. On the next drive around I stopped at an Euronics store and purchased an antiglare Puro iPad protector. Back to the hotel I cut the protector in half, and with the screen exposed applied it. Then trimmed around the outer borders of the screen with scissors, leaving even the contacts in the bottom part covered, and closed the unit with rubber gasket and bezel in their proper places.

The 720 hasn't had a single hiccup since then - it was late October then.

 

[canderson]

Hey, you want non-stingy, I can do non-stingy! :lol:

Great detail this time. One thing I'm curious about - it sounds as though you haven't had the unit all that long - perhaps as recently as last year. The 720 was originally sold in 2007, and the 730 came on-line in 2008. The 740 started to disappear entirely last year. When did you actually purchase the unit? I ask because I am wondering if you received a 'refurb' unit or a truly 'new' one.

The story on these units has been varied. Over the course of the last year or so, I've come to suspect that a lot of people who have had some success with the 'business card' solution were actually pushing the gray 'gasket' material away from the glass in the process of cleaning out whatever else might have been there. It's not clear whether the gasket material itself deforms or whether slight deformation of the bezel/case plastic is forcing the gasket material towards the glass. I strongly suspect the latter.

One of the things that we have confirmed with a couple of users is that heat plays a part in some of the failures - either summer heat on the windshield or winter heat for those who use ProClip or similar mounts to mount near forward facing heat vents. In the later case, we have had users reposition their units away from the hot air flow and the problem disappeared. That indicates that we are likely seeing the plastic warp ever so slightly with an increase in temperature. This temperature dependence leads one to consider whether the thermoplastic being used in the case/bezel components isn't attempting to take a new shape when heated that is forcing the gasket toward the glass.

We also have cases where ambient heat isn't the culprit, and where placing a unit into a cooler operating environment doesn't change things at all. In those cases, I suspect the long term exposure to higher temperatures over the life of the unit has slowly allowed the plastic to deform. There is some evidence that the heat radiated by the rather large heat sink at the top of the PCB of these models may be adding to the effect. I've experimented with that, but haven't been able to cause a failure from that component alone.

It also seems to impact only x20 and x30 units. Whatever change for the x40 and beyond, similar in construction as they are, we don't see this issue. The touchscreens are identical between x20, x30 and x40 units.

Another thing that we have noted over the years is that this problem does not appear until the device has been in use for some time. After the 720, 730 and 630 models were released here, we heard nothing about this. Within a year of each introduction, we would begin to see complaints about the 'phantom' key press, and the pressure was nearly always in the upper right corner - generating 'cop shop' instructions for the user due to the identical construction of the menus on these units. Initially, users reported back that working a shim of some sort under the bezel was resolving their problem, and we were not hearing of any repeat problems. Later, we began to note that the problem would return and perhaps could not be resolved by the shim method at all, even for brief periods.


If I understand your situation as it eventually played out, you were operating with the bezel in place...

Next morning I opened and cleaned it, it worked for a while and started misbehaving again.

... and finally resorted to complete removal of the bezel and gasket...

It was jumping around with the bezel and rubber gasket off, clean - nothing touching it.

. Later, you added the iPad screen protector and reinstalled the gasket and bezel.

and closed the unit with rubber gasket and bezel in their proper places.

Based upon all of our prior experience with this problem, I can only conclude that the Puro device did accomplish something in your case. Problem: the Puro product is from Italy, and not distributed anywhere that I know here in North America. I've done some homework in an attempt to find out which of the several 'styles' of screen protector material this is, in particular, how it actually adheres to the surface of the touch screen. Their web site does not include a section for support/instructions that would even give me a clue as to what they're doing - only lists and prices of products. Based upon their product mix, I doubt they are involved in the manufacture of the film they are selling, and are repackaging a film made by another company, further removing me from a description of what this material is.

Based upon my understanding of resistive touch screen technology, my only assumption is that the screen protector has reversed pressure in the upper right area as it 'dried'. Again, whether I'd be willing to believe that is an accurate assessment would require knowing which of the several film/adhesive techniques is employed in the product that Puro is selling.

Q: Was the Puro product applied with water or was it applied dry?

 

[rjsa]

As for the purchase, I'm not very sure. It happened early 2011 and via Amazon, that's all I can tell. I'm puzzled that my wife let this glitch slip, she usually does quite heavy research prior to buying online abroad. Let alone being fooled into buying past shelf life...

About the protector, it's your standard anti-glare dry self adhesive, with two peelable plastic sheets. Remove the first to expose the adhesive, the remove the second after rubbing it flat. I still have the other half, shuffling thru the package revealed that it was made in P.R.C.

What's noticeable for me is that every time I applied a new protector the unit would go stable. And the fact that it was shifting around while naked in the hotel room voids both present heat and rubber gasket/aluminum bezel interference.

 

[canderson]

What's noticeable for me is that every time I applied a new protector the unit would go stable.

Then you have applied more than one protector? Were they all Puro product? What led you to replace each of them? Did the unit go UNstable with a protector installed? Under what circumstances?

 

[rjsa]

Two before, from this brand:

http://www.skyzmall.com/iPad-Antiglare-BHB-Screen-Protector-Case.html

Not exactly this model, a black and blue package cut for 4.3 inch gps screens. I still have the package here.

First before I first disassembled the unit for the first time. The second with the bezel off.

 

[canderson]

OK - still a little foggy, but getting closer. Did you experience failures with other screen protectors on and the bezel off, but then experienced no failure with bezel on or off with the Puro installed?

 

[rjsa]

#1 - Brand new, no protector, fail->install BHB protector good until left on the floor.

#2 - Failing miserably after retrieved from the floor -> open for the first time, install second BHB protector, good until Italy

#3 - Goes crazy and fails even totally disassembled -> install Puro protector covering whole screen assembly, still working.

 

[rjsa]

New protector and bezel off is aways good.
No protector and bezel off not necessarily good.

 

[canderson]

#2 - Failing miserably after retrieved from the floor

Am curious. Was the car being driven with the unit on the floor, and what time of year did this occur?