Repair Canon 580EX?

[Al Blanco]

Hi, I have a Canon 580EX mkII flashgun and some time ago now the unit stopped rotating horizontally. I know there is a locking pin involved which is released when you press the release button on the side of the head to rotate/swivel up/down left/right and I'm guessing the issue is there. Having looked at the drawings of the insides I don't fancy doing that myself so I am am looking for an independent repairer one man show type work from home place who would know what the issue is and won't charge me more that what the unit is worth. I currently use it on a stand with a softbox and it doesn't need to swivel horizontally for this purpose, but it would be nice to have it working as it should.