tomina wrote:Thank u for help. Do u think that my problem its the SDHC card and not the device?

I couldnt really comment on that as i have only ever used sandisk cards and they all run great, i know some cards can cause such problems from user feedback but without testing the card in other devices it would be hard to give a correct answer

I can test the card in a mobile phone? If yes how? TomTom recommended 4 GB SDHC as maximum can i use 8GB SDHC ?

I use a 16GB ard and have no problems at all.
Slow SD cards are a common problem especially if you buy no name stuff.
I too prefer sandisk but I noticed that most users with problems in regards to their S cards also have formatted the card which is most likely the cause of the problem.
There are programs that do read/write tests but a simple video file of 300 or more mb is enough to stop the time it takes to copy.
But the speed of the card should be no problem at all - the first cards to be used in TT devices only had very slow speeds compared to the stuff you get these days.

So the problem can be the device ? And what do u mean by "formatted the card which is most likely the cause of the problem"?
Ok i find a soft and i test the micro SDHC card and found no errors and the read speed is 21,12 Mb/s and the write speed is 12,29 Mb/s. So its good this speed for TT to read the map in real time, or i need a higher speed? The micro DSHC is formatted in FAT 32.
I check the internal memory of TT 740 and found no errors and the read speed is 8,10 Mb/s and the write speed is 3,90 Mb/s. So where to look for the problem ? Please help me !!!!!!!!!!!!!!:helpsos:

The problem was the micro SDHD card.
Thank u everybody for help.