To be maximally pedantic, phones have neither hard drives nor BIOSes. For that matter, no computer made anywhere has had anything describable as a âBIOSâ since at the latest 2020, when Intel announced that they were finally removing and ceasing to support the âlegacy CSMâ (âcompatibility support moduleâ) which provided real-mode boot faciliies in the UEFI firmware on modern PC motherboards. Even before then, the thing described as a BIOS (a pile of almost-unmaintainable handwritten assembler which provided early boot facilities and some very poor driver-analogues to ancient PCs running MS-DOS) has not really existed for at least a decade, since UEFI took over and replaced it with a much larger and more flexible pile of code written largely in C. Unlike BIOSes this has a single reference implementation, EDK, that is largely maintained by Intel and that almost everyone else uses with minimal modifications. Unlike the BIOS of old, the UEFI bootloader is a full-blown operating system with loadable drivers and everything, which can even provide services to the OS proper once the OS is up. Unlike BIOSes of old these things usually have watchdogs so that if booting does fail they will try again (expensive server-class hardware hits these surprisingly often!). For that matter even desktop CPUs have watchdog timers these days, with pins that are monitored by other hardware on the motherboard and that triggers reboots or shutdowns to avoid further damage if theyâre asserted.
Phones have nothing like this â like most ARM boards smaller than a server they are booted via u-boot, which is a pile of C with extensive board-specific hacks. They do often have watchdogs of a sort though, because itâs much harder to just turn a hung phone off (the power switch is read entirely by software which is frozen if booting has failed or the system has hung).
And, of course, they have no hard drives. Flash RAM everywhere. This is not good for you: hard drives are basically immune to overvoltaging, though you might need to replace the electronics and possibly even the heads, which is expensive, the actual drive surfaces with the data on will probably be fine and there are expensive specialist firms that can get the data off.
But overvoltaging any sort of modern chip, either the CPU or RAM, is very likely to fubar it badly enough that they work at best erratically, which usually means that booting fails and, if youâre lucky, a watchdog fires and they try to boot again, only for that to fail, forever â you need to be lucky because usually Iâd expect this to fry the watchdog circuitry as well. Fixing this sort of thing is basically impossible even if you had millions to spend: overvoltaging, like hitting chips with static, causes scattershot damage all across chips and massive data loss / logic failures, and there are no facilities for fixing that sort of thing, nor any mechanism to do it. This is the downside of building things layer by layer using photolithography: laying them down is comparatively easy, if anything that requires multiple machines costing hundreds of millions of dollars each could be called easy, but fixing anything that goes wrong would require some different magic technology which doesnât exist yet and likely never will.)
OMG, no, thatâs not an option!