Something eating CPU on Sony XPeria XZ, how to find out what it is? I have two Sony Xperia XZ devices, bought both very recently in UK as used-with-warranty. One is working great, but the other (which has a 3 logo come up when booting) apparently has something using CPU all the time. Why I think so:


Phone is warm even when not used
CPU-Z and the like show frequency not falling under 1200 MHz, and usually over 1400 - while the other has it hovering under 1000 and sometimes hitting 330.
Antutu and especially GeekBench 4 results are worse than the "good" phone


So how can I catch the "perpetrator" and get rid of it? AVG and MalwareBytes scans find nothing. And the phone behaved like it was just factory-reset when I started it, so I'm not sure a factory reset would be of much help.
Use ADB and its logcat feature to see log of system and activity of processes.

Also you use adb shell top to see processes and consumptions