So a system restoration is a no-no? I better just leave it alone, then. I have a Slim model which I bought from a guy who fixed its module. That was 3 years ago, and it's still working. The only reason I'm afraid of asking him to repair it is that the Slim came with excess of (generic white) thermal paste and a potentiometer. I re-applied the thermal paste twice (once shortly after buying it and again one month ago) with Arctic Silver 5 and it runs very hot. The Super Slim (CECH-4214B) in question had a single owner and was never opened.
My initial idea was to jailbreak it and use a Mayflash Magic-NS to make up for the dead module and the LAN port, naturally, but I just found out that a NoBT/NoBD HFW is basically CFW and therefore impossible to be installed on this model.
So the only thing I can do is to wait for my Slim to die, that I doubt will happen any soon; despite shutting down at high temps sometimes under ambient temp of 35ºC, it is otherwise reliable, just very loud. It's a CECH-3001A unit, by the way, whose fan and heatsink were downgraded
* from the previous revision. Seriously, that heatsink is no different from the generic trash used in fake Chinese graphics cards. Once it die, I will pay to repair the Super Slim, so I can use it fully (that guy offers a warranty period of three months, better spent playing rather than idly).
My basic electronic knowledge is restricted to using a multimeter.

Thankfully, blackouts have not occurred so far.
* There are comparison photos posted on a thread called "New PS3 Slim model (CECH-3000B) cuts power consumption, weight, small cosmetic change", post #315. I can't post the link here for some reason.