How to replace fuses on Wadia S7i?

Has anyone done replacing the fuses inside the Wadia S7i or any Wadia product yourself? I have a S7i which stopped working one day. I'm suspecting it's the fuse that needs to be replaced but I'm not sure if I should send it to Wadia instead. I've contacted Wadia support but no reply for more than a week.

I'd be much appreciated if anyone can help, thanks