Bench Test / WeldKing / CoolArc200

Test intent

Confirm correct 110 V or 220 V input recognition and separate sense-branch faults from real output faults.
Prove normal VRD or non-VRD behavior before calling low OCV a failure.
Verify stable stick and optional TIG-ready baseline after repair.

Tools and setup

Digital multimeter
Clean steel coupon
Known-good clamp and holder
Stable input source matched to the test voltage class
Optional simple TIG kit only after stick baseline passes

Pre-power checks

Check	Expected condition	Result
Tested input source	known 110 V or 220 V source verified before energizing	pass / fail
Input plug and adapter path	no heat damage or loose adapter fit	pass / fail
Clamp and holder path	tight and clean	pass / fail
Fan branch at rest	fan is free to start and not mechanically blocked	pass / fail
VRD expectation	technician knows whether the test is in VRD or non-VRD logic	pass / fail

Electrical checkpoints

Checkpoint	Expected value or behavior	Record actual
J3 pin 2 to 7 sense branch on 110 V	about 3.3 V
J3 pin 2 to 7 sense branch on 220 V	about 0.3 V
Display input indication	matches actual input class
OCV in VRD mode	low safe-voltage behavior by design
OCV in non-VRD mode	may recover to normal after first weld rather than staying low indefinitely

Functional proof

Test	Pass condition	Result
Correct input recognition	display and behavior match the actual connected input	pass / fail
Fan startup stability	fan starts cleanly without blink-only or twitch-only behavior	pass / fail
Stick hot start	starts cleanly on a simple steel baseline	pass / fail
Short weld	stable arc without false low-output behavior	pass / fail
Re-power and retest	no drift back into wrong input recognition	pass / fail

If it fails

Sense voltage wrong: stay in main-board input-detect branch.
Sense voltage correct but display wrong: stay in control-board branch.
Low OCV only because VRD or sleep behavior is active: not a power-stage failure.
Blink-only display or no stable fan start: isolate the fan branch before control-board replacement.
Light and fan present but no true output: keep control and output branches separate from the input-sense issue.

Direct official parts pages

Use these only after the complaint has been proven to follow the input adapter, TIG-kit, or current-path branch instead of the control or output stage.
CoolArc200 parts category: official CoolArc200 parts path
TIG welding kit 07003750: official product page
230 V to 125 V input adapter 07001825: official product page
Ground clamp 07000462: official product page

Post-repair release

Signoff item	Result
Correct voltage recognition proved	pass / fail
Fan starts and stays stable	pass / fail
Output behavior matches VRD or non-VRD expectation	pass / fail
Stable stick baseline restored	pass / fail
No heat at plug, adapter, clamp, or holder	pass / fail

Technician: __________ Date: __________ Serial or shop tag: __________