Instead of returning it for service, I consider repairing it myself, as the battery and back cover sealant costs no more than 25 bucks together (OEM), and the back-cover is loose because of the hot phone issue. But where are the Warranty VOID stickers? I know about the water indicators in the openings of the phone, but several phone service shops, youtube videos and even Sony Support themselves said that the only warranty void indicators are those water indicators.
Basically, Sony's reasoning was that they WILL see it when someone unauthorized has been inside the phone. When I asked if they would notice if the repairman would use OEM parts and leave no traces behind, they simply said "Your warranty is void if an unauthorized person services the phone". Which to me sounds "Yes, but I have to say no".
So, are there any? How would they be able to notice?