DVMEGA upgrade from Pi-Star 4.1.4

[g4txk]

I have been trying to upgrade my DVMEGA single band hotspot using the flash from Pi-Star method.
But no matter how I try I get the same problem. I have seen there was an issue with 4.0.0. But I wondered if that had been solved.
I am trying to upgrade from HR2.28 to V 3.19. I get the following prints when I run the ./flash_gpio.sh command.

pi-star@pi-star(rw):dvmega$ sudo ./flash_gpio.sh
Warning: Stopping pistar-watchdog.service, but it can still be activated by:
pistar-watchdog.timer
Warning: Stopping dstarrepeater.service, but it can still be activated by:
dstarrepeater.timer
Found DVMEGA_RH_V319_UNO.hex firmware...

avrdude: Version 6.3-20171130
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "/etc/avrdude.conf"
User configuration file is "/root/.avrduderc"
User configuration file does not exist or is not a regular file, skipping

Using Port : /dev/ttyAMA0
Using Programmer : arduino
Overriding Baud Rate : 115200
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding

etc etc

Anyone able to help. Before I have to bite the bullet and buy a new unit.