Heya folks. I think I posted a while back about this so apologies if that is so. I am still getting nowhere fast with my issue despite masses of internet searching, my brother in law who is a mechanic looking and even calling my local Subaru dealer.
To update, my battery was replaced because the old one died. This caused the stereo to stop working. Theres no fuse issue, as it still has power. It just displays the message "Program is attempting to load please insert SD card". When I bought the car it did not have a card, I wasn't worried as I just thought it was for the sat nav, which frankly, is awful on the Subaru head sets. It looks like the stereo is ok, ie not fried, as it has been "plugged in and checked" but apparently needs its SD card to effectively "boot it up".
I found this site: https://subaru.oemdtc.com/TechnicalSupportGuide/MC-10065756-3639.pdf which has a nice list of sd card part numbers, but I think it is for North America and I cannot find anything for sale.
To be honest, I would sooner just put a new stereo in, as the Fujitsu piece of crap that is in there (it is the same as the one pictured in that link above) is not a great stereo anyway. But in the days of Can Bus stereos I have no clue what I can fit, if I can fit, and if it will work with the rear camera, which if I am honest is the thing I miss the most.
Any ideas? Either on how to rescue my current stereo, or what I can fit in its place? It's driving me nuts!