Guys, THANK YOU so much! That saved me 200+ €.
My pedal on the FBV3 was dead for the above reason, too. It was quite fiddly to get this little piece of LED attached with a standard soldering iron and a pair of tweezers. However, it worked on the first try. Now it shines brightly again and I've got back my wah!
Although I now have some of the LEDs in stock, hopefully that'll hold the 5 Volts for a while.
Thanks again,
Fil