Over the time i received a lot of Raymarine I70 and P70 devices with faulty pushbutton boards. Water comes in and over the years (usually 2,3 years) board gets eaten away. You can see some examples in photos (green boards).
Repair is possible, but it is not worthy because you lose a lot of time that you can not charge, and over the few months it happens again... Of course as always, spare part is not available from our beloved factory so you need to buy whole new instrument for 600, 700 euros... So I made my own pushbutton boards... Black color because that is the color of my soul. I copied a design from original one, sent drawings to PCB factory in China. PCB's are proffesionally made with coating and silk layers with tolarences 1/10 mm. What is left is solder the pushbuttons and headers in place... Fits like a glove 
