Page 6
Check Fault
Faults
Resolvable Methods
Power indicator is not lit, fan
does not work and no
welding output
1. Power switch not working.
2. Check if electric wire net (which is connected to input cable) is working.
3. Check if input cable is out of circuit.
Power indicator is not lit
1. Wrong connection to 380V machine is in protection circuit, connect to 220V
and operate machine again.
2. 220V power is not stable (input cable is too slender) or input cable is
connected to electrify wire firmly. Close machine 2-3 minutes then open it
again.
Fan is working, indicator is
not lit and sound of HF arc
striking cannot be heard,
wiping welding cannot strike
arc
1. Positive and negative electrodes of VH-07 insert component voltage should
be about DC 380V from power panel to MOS board.
2. There is a green indicator in auxiliary power of MOS board, if it is not on
auxiliary power is out of work. Check fault spot and connect with seller.
3. Check if connectors have poor contact.
4. Check control circuit
5. Check if control cable of torch is broken.
Abnormal indicator is not on,
sound of HF arc-striking can
be heard, but there is no
welding output
1. Check if torch cable is broken.
2. Check if ground cable is broken or not connected to welding piece.
3. Output terminal of positive electrode or torch is loosened from inner-machine.
Abnormal indicator is not lit,
sound of HF arc-striking
cannot be heard, wiping
welding can strike arc
1. Primary cable of arc-striking transformer is not connected to power panel
firmly, tighten it again.
2. Arc-striking tip is oxidized or too far, give a good polish to it or change it
about 0.04” (1mm) between arc-striking tip
3. Switch (sticking/argon-arc welding) is damaged, replace it.
4. Some of HF arc-striking circuit components are damaged, find out and
replace
Abnormal indicator is lit but
there is no welding output
1. Overheat protection, close machine first, then open again after abnormal
indicator is out
2. Overheat protection, wait 2-3 minutes (argon-arc welding does not have
overheat protection function)
3. Inverter circuit is at fault, pull up the supply power plug of main transformer
which is on MOS board (VH-07 insert which is near the fan) then open
machine:
(1) If abnormal indicator is still lit , close machine and pull up power supply
plug of HF arc striking power source (which is near the fan), open
machine:
a. If abnormal indicator is still lit MOS board is damaged , replace with
same model
b. If abnormal indicator is not lit, rise transformer of HF arc-striking circuit is
damaged, replace
(2) If abnormal indicator is not lit:
a. Transformer of middle board is damaged, measure inductance volume
and Q volume of main transformer by inductance bridge (L=0.9-1.6mH
Q>35). If volume is too low, replace
b. Secondary rectifier tube of transformer is damaged, find faults and
replace rectifier tube with same model
4. Feedback circuit is broken
Output current is not
stabilizing or out of
potentiometer control and is
sometimes high, sometimes
low
1. 1K potentiometer is damaged, replace
2. All kinds of connectors/inserts have poor contact, check
Sticking spatter is much and
caustic electrode is difficult
1. Electrode is connected wrong, exchange grounding cable and handle cable
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