Re. Xenon DEATH FLASH!!!!!
I've also noticed the same effect on Aurora calculators, ie Poundland el cheapo ones.
The culprit is the transparent case and chip mounted on the back of the board as is common with such things.
It does occur to me that as many 'phones use the same construction it could be an interesting way to insert intentional glitches into the running system for the purposes of finding vulnerable sections in the firmware.
Biting the hand that feeds IT
