I don’t know if this will be helpful for your situation but my keypad on my Alpha is very similar to yours and I thought my keypad was bad a couple of years ago. I dug deep into my Legend file and found a keypad cheat sheet from the dealer when I purchased the boat. I had somehow placed my keypad in sleep mode and once I got it woke up again I haven’t had another problem since. I think I placed it in sleep mode by holding the power button down for an extended time but I can’t be 100% sure on that.
Here is what I would try before you go down that road of searching for a used keypad or even worse putting in a toggle panel.
1. Reinstall your keypad.
2. Turn ignition switch to on position to “wake” your keypad.
3. Press the power button once very briefly on your keypad.
Hopefully you now have power to your keypad. I’ve attached the cheat seat I had in my file. I hope this helps, but even if it doesn’t let us know how you got back up and running.