So you replaced the Z sensor and it still didn't work. You can check it's functioning by putting a screwdriver underneath and then the small led on it lightens up.
If it doesn't lit up, then either it's not powered (and so you must check its connection), or the board has an issue, you can try to flash the firmware first.
Was that before or after you fried your board ? You still have the metal bed, right ? Is your harness routing ok and stress free ?

Yes, it is written all over that PB support works by mail : it has the advantage you can send a detailed description with photos and videos. I find they do answer fast though. But I guess it's a US thing that people expect a voice over the phone. In my company we have 20 subsidiaries providing support all over the world and only the US one has a call center.