it is not repairable this is a common fault with this bike,the units are sealed and although it may be a track burnt out internally(and potentionally repairable) they are vertually imposible to get into without damage trust me i have tryed, i have two waiting to be done myself,there is also not much point buying second hand unless you can be sure they work,really you want to be buying a new one you can get them on ebay aprox £120(new) hope this helps regards mat
mat
January 2009