Geeetech

Dear friend,
Could you please tell me whether you can find com port or not when you connect DUE and Computer?
If not, maybe there has problem on 16u2. You can use usbtiny to upload bootloarder.
If you can find com port, the mcu probably has problem.
Waiting your reply. Best regards.

Dear friend,
Could you please use USB to connect DUE and computer?
Please note that don't connect to FD and other peripheral device module.
Waiting your reply.
Best regards.

I understand what you mean. Now I have hunted problem and software port D7/8 are between arduino and GSM shield. Serial port D0/1 are only used for debug.

With this code I found that some reason I have GSM shield where baud rate dont stay in same speed.
#include <SoftwareSerial.h>
SoftwareSerial ...

Dear friend,
You can pull out jumper caps on VIN, and then use USB supply power.
Best regards.

Dear friend,
Could you please download Driver Genius?
This is the link:
http://www.drivergenius.com/

Best regards.

Dear friend,
Could you please uninstall the driver first, and then follow the steps:
1. Remove FD, remain DUE only, and please don't connect DUE with Computer.
2. Upload the driver via this link:
http://www.driverscape.com/download/arduino-due
3. Plug DUE again, let it installed automatically ...

Dear friend,
Could you tell me what computer system you use? Is it mac?
Because our bootloard is suit for Windows system, so if your system is mac, you need upload bootloard by yourself, you can refer to this link:
http://www.youtube.com/watch?v=GMt4hLaKjAc
Or you can use the computer which use ...

Dear friend,
JP1 VIN and JP101 VLOG need plug jumper caps.
I attach the pictures.
Best regards.

Dear friend,
The hotbed is fixed with spring screws, you can adjust the level of hotbed by adjusting the screw.
Best regards.

Dear All,
One of our customer shared his experience with the GSM/GPRS Shield on our forum, could you please see whether can solve your problems or not?

This is the link:
http://www.geeetech.com/forum/viewtopic.php?f=9&t=15861

Wish all of you a nice day.
Best regards.