hi there - i have an old castotig 200 tig welder - i'm told its a fronius clone - anyway on with my tig - it was not working on the high frequency for ac welding so i cleaned and reset the spark air gap contacts as they were bably corroded - checked all 14 fuses - came to the last one - blown - so replaced - high frequency worked a treat for a few seconds then blew fuse again -was able to get it working again by replacing fuse but as soon as more current was supplied fuse blew again -the gas solenoid and main contact relay stopped at the same time so must be on the same circuit - can anybody point me in the right direction - i have a schematic if this would help? -does anyone else have one of these machines , maybe a manual? any help / suggestions would be appreciated