:lolIts fooked. Sell it and buy a GS1200. :lol
Its not as easy as the above link suggests as its a sealed unit and you have to pry it open with a screwdriver or something similar and it leaves marks. I have opened a couple up.
Presumably you are out of warranty so you either grin and bear it, fix it and cause a little scuff round the outside or buy a new set.
How to fix those f'oggin gauges
It's a common problem.
Put misting clocks in search and loads of info comes up.