Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
Question, are you using the Garmin in an aircraft to fly? Or do you have it loaded with simulation software for training purposes?
My apologies for the delay.
When you say the back screen.. Is it the top, or bottom screen on your 430W Waas unit that is out?
Its been 4 minutes since my last response. On my end, I was going over the manual since I dont have that device sitting in front of me at the moment, and I k now the 400w series had slightly different menu / button combinations then the 430.
With that being said, considering the sheer cost of one of those units our cost of 34$ ( not 5$ ) is more then fair considering most GPS repair outlets would charge 125$ Just to look at those units.
So my question before I put forth any suggestions is this, do you want the refund link now? Or do you want to continue?
All right, here is the refund link
Best of luck to you!