how to destroy old mobiles stored data

I have a few old Mobile not working so i can not access to Stored data. I want to give them for decoration purposes to a designer friend but i would like destroy before all internal data if possible without damaging case.how to do?

Disassemble them WITHOUT damaging the cases.

De-solder (or cut the pins of) any chip.
You may want to alternatively grind down a few chips here and there, if you don't have a GCHQ computer or phone expert handy for pointing which ones to grind
http//www.forensicfocus.com/Forums/viewtopic/t=10944/
you may well do by grinding a few random chips, the use of a verified random generator such as
http//xkcd.com/221/
is advised.

RE-assemble them (still WITHOUT damaging the cases).

jaclaz

Alternatively use a video tape degausser; completely wipes all the memories. Works just as well on computer hard drives.

Alternatively use a video tape degausser; completely wipes all the memories. Works just as well on computer hard drives.

Really?
A degausser affects (non magnetic media such as) flash memory? 😯

jaclaz

Based on the paper by Wei et al. degaussing does not affect the data in Flash memory.

Based on the paper by Wei et al. degaussing does not affect the data in Flash memory.

Sure it doesn't.
More here (JFYI)
http//reboot.pro/topic/13601-software-to-wipe-a-systemdrive-from-windows/?p=123082

jaclaz