Hi can anyone help ive up loaded the firmware update the latest one but only get 20ft in height with no signal all the time.i was then told to downgrade to the 1.5.70 and was better but only get 150ft can anyone help with this problem

Please watch this video to see if it helps you any.
If you can only get 20ft then something is definitely not right.
What are are you flying in, can you try an open field?