Help figuring out broken inverter arc welders

[Ruffian]

Hey all wondering if anyone can help me,

I have been given 2/3 inverter arc welders with the challenge of trying to boot them back into life. All are semi decent machines, (inverter fusion 130, tecarc 160)

At the moment the inverter fusion will power up but only getting 1.7v across the dinse plugs,
Need to look at the tecarc properly to see what it's doing.

What is the best way at diagnosing these machines as spoken to a few repairers and they said it's not worth paying anyone as the machines are so cheap and "disposable" (well in their eyes)

Any help is appreachiated.

 

[R Kraft]

The ones that I have seen all seem to follow the same basic plan.
A capacitor bank is charged through a resistor that bypasses the power relay.
The charged capacitors run the plus-minus power supplies.
Be careful of the capacitors, they will have about 308v and may hold a charge quite a while.
Most of the small inverter welders are copied from the JASIC design, patent US 2014/0209586 A1
I could send you some links to some of the block diagrams.

 

[bwservices]

is that ifl the handbag shape or the usual welder look?could be final stage rectifier diode failure
what happens when you turn on the tecarc?

 

[Ruffian]

Usual toaster shape welder if that makes sence?