why is the fuse on the dyson circuit board blowing its a 10 amp 250volt gla?

you may have a blown triac.
i have found that dry solder joints on the bridge rectifier will cause it to fail short circuit blowing the fuse.you can repair this using parts from component suppliers.be careful of the type of triac as some have a live tab and will need in insulator fitting to prevent a short to the diode on the heatsink.when repairing the board resolder all the connections on the high power side to prevent the problem reoccuring.use lead/tin solder as the leadfree type seems to cause dry joints
i hope this helps

chris
February 2009