04-03-2012 12:16 AM
Usually a digitizer fails slowing with the simptoms that you touch in one place and the touch registers in a different place on the screen, Of course it is possible for a complete failure where the digitizer is way off in left field. Regrettable there is not function that outputs the actual X-Y position when you are touching the screen.
But before assuming that the digitizer is a problem I would at least format the memory of the gps and reinstall the gps software.. If the unit starts working I would then download a new map. This may be one of the items customer service has given you to do. The important thing to remember when you format the memory (FAT32), is that you will probably need to perform as many as three updates before the unit is working correctly. You need to disconnect and restart the gps between each update.
Don't freak out after the first couple of update if the display is unreadable. This is not unusual, just plug the gps into the computer and reset the gps to get it to connect to the pc without needing to go thru the "Do you want to connect to the computer" screen.
FYI, if you still feel the digitizer is not working, it is possible to replace it. The easiest way is to replace the entire screen / digitizer as a single part. If you do this yourself it will cost about $50 to purchase a replacement screen. If you are really handy it is possible to replace just the digitizer for around $15. But this requires some soldering. If you want to replace the screen or digitizer I can provide information as to purchansing of parts and installing them.
04-03-2012 11:32 PM
i had a friend who had a tomtom with a digitizer that went bad. It sort of deteriorated over time. It happened occasionally, then he'd pound on it repeatedly and finally get it work, and then after a while it just stopped working altogether and he got a used one from a friend to replace it.
My problem seems similar, but a bit more sudden. A couple times I have managed to press it in one spot and I've had it repond in a different spot. But mostly it just doesn't register any touch at all. That makes me think it's the digitizer.
Will taking anyone's advice fix the digitizer? Or is replacing the digitizer the only way to fix it?
It's hard to follow any of the advice I've been given, because I can't press any buttons!
I found one place I may be able to mail it to and have them do the repair.
I have also considered just ordering the part and doing it myself. A few parts of this sound tricky. Like how do you separate the old digitizer from the screen? How do you line up the new digitizer perfectly? What if it goes wrong and I end up with the same problem? And I have no idea just exactly what needs to be soldered...
i wouldn't mind taking a look at the digitizer info. you have if you want to pass it along.
I wonder what makes a digitizer go bad in the first place. is there any special care a person can take to guard against that?
05-03-2012 07:25 AM - edited 05-03-2012 07:59 AM
The digitizer on your model is referred to as resistive sensor. It consists of three parts. A very thin glass sheet, a plastic sheet (the part you touch), and very tiny silicon rubber beads silk screened on the glass sheet. The two sheet are sandwiched together and the rubber beads act as a separator. The inside surfaces of the glass and plastic sheets are coated with a thin resistive metal film. When you press on the plastic sheet you make electrical contact between the two resistive films and the electronics can determine the X and Y points where contact was made. Typical failure mode is caused by micro fractures in the metal film.
The digitizer is held in place with a thin double sided adhesive tape. To remove the digitizer you simply slip an Xacto blade between the glass sheet and the LED display.. Working the blade around the perimeter of the display until the digitizer comes off. Normally you end up cracking the digtizer getting it off. The electrical connection of the digitizer is a small flat ribbon cable. This is soldered to the main display ribbon cable. It is best to cut the digitizer cable before removing the digitizer. Once the digitizer has been removed, unsolder the little cable from the main cable ( 4 solder points ).
The new digitizer comes with the double sided tape already attached. Aligning the digitizer to the display is the easiest part. Just dry fit it a couple of times, before removing the backing on the tape. On the Samsung displays there is a plastic channel on one side to assist in correct alignment of the digitizer.
Here is a TomTom display that I replace the digitizer. It should give you a better idea what you are dealing with.
Here is a video where the digitizer is replaced.
1. You will see him first remove the plastic sheet and then remove the cracked glass sheet.
2. Then you see him unsolder the ribbon cable and solder the new digitizer to the display
3. Last he mounts the digitizer to the display.