Wifi won't turn on on stock or custom roms.

Hi, we've got the old S2 out a drawer to lend to someone, it's not been used for 6+ months but worked fine then, the wifi no longer works, it thinks about turning on for about 10 seconds then switches back to off. I've tried a factory reset, I've tried CM12.1, tried going back to a different stock rom, still nothing at all, all does the same. Done lots of googling and people say to enter *#*#526#*#* to see what the wifi test says but that code doesn't work for me on 4.1.2, just get a sorry this number is not available.

Any ideas, be good to get it working.
Thanks.