CoolArc200 Input-Sense Drill

Drill Goal

• teach the trainee to separate wrong input recognition from true output failure
• teach the correct use of VRD and first-weld wake-up behavior

Starting Scenario

• Model: CoolArc200
• Complaint: machine is fed with 220 V but seems to act like 110 V, and OCV looks low
• Arrival condition: the user also reports odd fan or blink behavior

Expected Document Sequence

1. CoolArc200 measurement card
2. CoolArc200 fault workflow router
3. CoolArc200 board opening map only if J3 and state proof still leave the complaint machine-side

Success Criteria

• the trainee says the first proof step is actual input plus mode-state proof
• the trainee names J3 pins 2 and 7 as the clean split between sense and indication
• the trainee does not call low OCV a failure before checking VRD or wake-up behavior

Common Misses

• treating every low-OCV complaint as a bad output section
• skipping the fan branch when startup blink behavior is also present
• opening the machine before the input and mode story is clean

Debrief

• The key lesson is that this model punishes rushed diagnosis. State behavior, input sense, and fan issues can all mimic a dead machine.
• Internal opening is justified only after the J3 split and mode interpretation are already clean.