How to repair Roland SPD-SX power issue - FIXED!

SPD-SX not powering on properly? After over a decade of use, mine started playing up which is apparently a known issue (something Roland fixed with the new Pro model). I couldn't find anything online about it so wanted to put this out for anyone else having the same problem. All you need is a soldering iron and hopefully better soldering skills than me! I've used it on several gigs since repairing last week and it's been flawless, much to my delight. Special thanks to Christophe at Roland Europe for the help.