GT A-6 charger not working!

[naynay12]

Well i was balacing my 5000mah 5s flightpower lipo at 9.8A for the first time(i normally just do 5A,but have found the pack can withstand 5C),and i came back about 35minutes later a the pack should have been charged,though my GT A-6 charger from hobbyking was turned off.I have tried switching it back on to no avail.Is this a common problem,do i need to reset somehting,or is it a fault and i need to return to hobbyking?
I am also using a suitable power suppy,(hobbyking A20)and even though that seems to get very got(about 250F for the outer metal casing) it worked fine until now for about 6 or so charges. I doubt it is the power supply as when i turn the powersupply on the screws on the charger sti l"zap" me when i touch them indicating their is electricity running through.