Ghost tapping on Go 720 series, Calibration error

[kimski]

Hello,
I've been reading lot's of articles about the GO720 erratic misalignment when tapping a point and on how to adjust it using the CAL.TXT file with the 4 numbers. ( Mine reads 85 931 139 844).
Problem is that i've used the notepad solution and put my numbers in is as 931 85 844 139, saved it into the root directory on my device ( i don't have a SD card installed), via Windows Explorer.
The CAL.TXT file is present on the storage location of my tomtom, but when starting the tomtom i don't see any changes in the figures. I believe my device don't take the CAL file into account.
Moreover, as said by other users, also mine is so far OFF that i even can't tap the langue selection from the start. It's completely mis calibrated, far off.

What can i do to recover?
Is there a way to reinstall the original factory software? In that, i believe that the screen coordinates must be ok not?

Thanks for the help.

Krgds
Kim

 

[dhn]

Have you seen the following?:

https://www.tomtomforums.com/threads/screen-re-calibration.29230/#post171227

https://discussions.tomtom.com/en/discussion/609564/touchscreen-calibration-my-experience

Also, check back later, Moderator canderson will likely see your post and respond. He is a guru in this area.

 

[kimski]

Yes i did, but it seems that my CAL.TXT file is not taken into the boot sequence. Post transferring the Cal file, i still see the same numbers as before. What could be the reason for this?

 

[dhn]

See if naming the file CAL.DAT helps.

 

[canderson]

Yes i did, but it seems that my CAL.TXT file is not taken into the boot sequence. Post transferring the Cal file, i still see the same numbers as before. What could be the reason for this?

The numbers you see on the black and white screen do NOT change. That screen will always report the factory numbers. Your file is modifying those numbers, but they do not change on the diagnostic display, ever. When you boot to the diagnostic display, the boot has not progressed far enough to see your file.

 

[kimski]

Renaming the CAL to a CAL.DAT file does not help. I have a strong impression that my screen is lost.
As the unit is aged already, where would I get a replacement at a low price? It's not worth to invest 25 euro's or more.... It's only worth when the replacement part is at low cost.

 

[kimski]

Would it help to install a previous software version? And if yes, where can I find it?

 

[canderson]

No, a previous version is going to be problematic. It won't properly know the date/time -- a long story.
One thing I want to be certain about is that the file is not actually called cal.txt.txt. If you have hidden the names of file extensions (something commonly set in Windows), that could be the case. Then, share the actual content of the file you have created with us, along with the numbers from your diagnostic screen.