It seems many Z2s have creaking and touchscreen problems, sometimes developing after some days of use.
In addition, a lot of Z2 Tablets seem to suffer of a warped, bent chassis: Just peek along the sides of the Z2, check if it's bent, curved.
My Z2 had NO creaking and NO touchscreen issues right from the start - but both problems came up after about two days of use, both issues showed up at the same time. And my Z2 is a "banana" Z2, it's chassis is bent, putting the device under constant physical tension.
Maybe there's a connection; let's find out !
Please reveal the following:
1) Z2 Tablet model (Wi-Fi/LTE, RAM size, serial number*, date of manufacture - see below)
2) Firmware version
3) Color (maybe different backplanes cause different stress on the chassis)
4) Market (Europe, USA, Asia, etc. - have a look at the box the Z2 came in; there's an information about the country it was made for)
5) Country of manufacture (I guess it's China for all Z2s produced - but you never know...)
6) Days of use
7) Bent ?
8) Touchscreen problems ?
9) Creaking/loose feel at the bezel (especially at the right hand side, in landscape mode) ?
10) Only if you dare: Bubbles emerging from the bezel area (not speakers) if submerging the Z2 ?
* Serial number: You don't need to mention the full number. Just have a look at the sticker on the box, "SN –": Example: 430101690000142
"141" is the serial number.Replace the last two ciphers with an "x". Result: "1XX". If your serial number is "54321", use this: "543XX"
This way, you don't have to reveal your full serial number - but we still get an idea of the production batch number.
Date of manufacture (thanks to LitoNi for pointing me to this):
This is how it looks like if your Z2 is bent: