Eratic change of display

[Frank Shannon]

Hi everyone and hope some whiz kid can help me. I have a Tom Tom Rider 450 on my motorcycle which is hardwired to a switched live via the Tom Tom Anti theft mount. In wet conditions the dispaly becomes eratic changing to various screens without any input from me. I disconnected the mount feed cable from the switched live and covered that end with plastic tape to seal it from weather conditions and run the unit from its internal battery. The eratic display change continues when riding in the wet. I suspect water is getting behind the sat nav unit onto the protruding connecting pins from the mount and shorting the unit, or has the main unit now lost its waterproof capabilities? Would appreciate any help to resolve the problem without having to replace the unit or mount or both.

Frank Shannon

 

[canderson]

I'm pretty sure that the 450 was a capacitive screen like all other Nav4 devices. Still, I'm going to recommend, just in case, that you take a business card or similar thin non-scratching shim material and clean out anything that may be under the bezel area on top of the glass. Then be sure the screen itself is clean. Rain water isn't very conductive, but any contamination on the screen surface can make it so. Just one thing to eliminate as a potential issue.

What I think you are seeing, as opposed to water incursion into the works itself, are what we call 'phantom screen presses' caused by something (other than you) having an effect on the surface of the touch panel. Way back when, we had one model (the GO 630) that was notorious for this, but it was actually due to heat warping the bezel. That was back in the resistive screen days, though, when any contact at all was a problem. The crud-under-the-bezel was more of a mechanical issue back then, but could be a conductive one now.

 

[Frank Shannon]

Thanks for your suggestions which I have carried out. I have also changed the screen protector as well. Not had the chance to test the unit yet.

Frank Shannon

 

[canderson]

Ah, wasn't aware that there was a screen protector involved. Would have been interesting to see what it did before a new one was installed ... just in case.
Let us know how you make out. You're definitely describing what we call 'phantom' screen presses.

 

[Frank Shannon]

Will do. I live in England so won't have to wait too long for wet riding conditions. If the eratic screen displays continue, would it be worthwhile removing the screen protector to see if that makes any difference?

 

[canderson]

Yes. I'd try that to eliminate it as one potential source of trouble. We need to see if an expected problem (see below) is being exacerbated by something 'new' to the equation.

It doesn't surprise me that water on the screen will sometimes cause this problem in any case. It's a known issue for many capacitive screens if there's enough going on on the surface to keep the firmware from sorting it all out >> https://www.popsci.com/why-does-drop-water-confuse-my-touchscreen/

If you're up for a far more technical explanation >> https://www.eetimes.com/the-basics-of-waterproofing-capacitive-touchscreens/#