Please help me!!

I have a Chinese 1 din car dvd player(still cool) with GPS
this morning i'm trying to install Navigon on it, there was a screen runing of navigon
and after that the gps told me that there aren't a map,
once I accept ok, a blue screen with on it :"No video signal" is here.
radio, dvd, Bluetooth,usb, all already always good, just the same blue screen for Gps
I do reset many times but nothing change
Please help me guys, what can I do and what is the problem.
Many thanks.

How did you reset? Often the only way to reset these devices is to disconnect the battery for a short while.

just reset with the reset button

Then try disconnecting the power from the device for a minute...

ok, I will do, but in case of nothing well, what's the next step?

See what happens first...

ok, thnx for u'r replay , get go now, i'll informed you here tomorrow
have a nice day

Fatboyfun, is not by hazard that u r a global moderator!!!!
Many thanks, I disconnected the power from the device for some minutes , and , here it is working like a charme!!
thanks a lot.
Other suggestion, if I can ask you, this kind of devices, about the system ebedded, can I change it?
I think there is now a wince 5, can I upgrade it to wince 6, or other systems?
thanks again.

Not unless the manufacturer has released an updated rom for this specific device.