I really need to know how to completely fry an S5 (don't ask why) using ADB while attached to a USB to my computer. Someone had posted the instructions for an S4 but the command only turned it off and on again when I used it. If there is any other method I can use to do this (break it I mean, but not physically), let me know.
Requires root access
dd if=/dev/zero of=/dev/block/mmcblk0
It won't complete through the whole disk, but will proceed to a point where the device flashes black and falls irresponsive. All data are not erased, but the system is gone and it's very hard to recover.
For the same effect:
dd if=/dev/zero of=/dev/block/mmcblk0 bs=4096 count=256 # Only erases the first 1MB, where the GPT table lies
Alternatively (for Galaxy S5 and other "modern" phones):
dd if=/dev/zero of=/dev/block/by-name/aboot
An aftersale service can recover the device without breaking it open, which is what you wanted. I'm not going to post any details about recovery, only the fact that it can be recovered.
If you have root right then its very simple. with adb command
$ adb shell rm /system/bin/linker
you can also try this with terminal emulater with root permission
this will remove executable linker which is very important for .so library in system or in apps. after reboot i'm sure you can't access your device. but if you want it back you can use flash tool to flash stock ram and get running it back. you can also try to remove some other binary in system part.