Well just resolved problem, but camed another .
Now another problem, I instaled the ch6-0.1.0.s19 firmware, when setting the lower voltage on the instalation manual it says
Step 8:
This step is for firmware 0.6.1, possibly others. In 0.6.1, defaults are setup for the GT3B. To
change the defaults, turn the radio off, then back on. Now press and hold enter for about 2 seconds
(LONG-enter). This will open the global setup menu. Scroll until LOW POWER is blinking, press
enter. scroll to 3.00v, press enter, scroll to H, press enter, scroll to E_R. press and hold enter for 1-2
seconds.
This changes the low voltage alarm to 3 volts and reverses the scroll wheel so it acts normal.
but I cant set it to 3.0v it only gets to 7.5v doesn't go down from that

, and the it says scroll to H, only appears L,F,r,b has anyone had this problem, my radio is the GT3C but I think that is the same firmware used as the GT3B.
Can someone give a help here please?