Inspire 1 controller Issue

Hi

Slightly new to the Inspire world. I bought an Inspire Raw second hand, and whilst going through checks the slave controller is just intermittently flashing between pinky/purple and blue. It appears to be disconnecting from the Inspire and reconnecting. I have checked the firmware on the Inspire and that is current, the master is on 1.7.80 but the slave is 1.6.00

I have tried to update the firmware...it is telling me I need to as well....but when I click on the firmware update it changes screen and that screen is blank. I have spoken to DJI support and they said use the latest firmware on to an sd card and boot up the aircraft. I have attempted this, but unsure how to know if it is doing anything as it said keep the controllers off. There are no lights on the X5R that I can see either.

I have tried putting it in the USB slot on the back of the controller...but that doesnt seem to offer any success.

Can someone help me please...Im hoping I dont need to send everything off to DJI for them to look at it.

Thanks

Jonty