AusFclass said:plus 1 on the millar gear!
im a accredited pressure vessle welder in australia and have used and destroyed plenty of welding equipment while at work.
i purchaced a millar dynasty 200 ac/dc pulse for myself at home and have to say its probably the smoothest welder with the most stable arc at low amps i have used.
because most of the new welders use inverter technology they have plenty of circut boards and gizmos inside. what usually happens is metal grinding sparks and dust get drawn into unit and short out the boards. keep the welder covered when not in use and every 3-6 months take the outer caseing off and give it a good blow out with the compressor.
also check that the plugs on the welding cables ( that twist into the welder) and earth clamp are in good condition. poor connections create heat and earthing problems all are not good for modern inverters.
by buying a well known brand you will be able to purchase replacement parts and be able to have the welder repaired locally if required.
good luck!