Is there anyway to go back to the first factory settings?

[Jester1964]

I've tried and tried to get my P4 back to the way it was prior to the terrible GO4 forced update and I always get back to the same rubbish signal. The earlier hacked SDk's dont even show a P4 once the4y are installed and think I have a P3 Pro so I cant use them!!! Something has gone seriously amiss and I just cant crack it. I cant even roll back to 1.6 as it keeps saying update failed

I have a Nexus 7 thats been working fine and its on DJI's approved device list so I'm doubting its the tab to blame.

Help!!