A100 Board Opening Map

This is the fast internal opening map for A100 once branch power, clamp, and holder branches are already bounded.

Open Only After Proving

stable 120 V class source is already proven on a real 20 A branch or healthy 3 kW generator baseline
known-good clamp and holder path are already proven
dry 3/32 in 7018 or 6010/6011 proof rod is already tried
lead polarity is already matched to the actual rod test
the complaint is already separated between dead-machine, no-OCV, or blinking-light behavior

First Internal Targets

Board or internal group	Open first when...	Key connector or checkpoint	Best local file to open first
Switch and low-voltage supply branch	the machine is dead but rectifier DC is present	dead-machine split with upstream DC still healthy	workbook sheet `A100`
Output or IGBT branch	OCV is missing with healthy upstream DC	output branch after current path is already proven	workbook sheet `A100`
Fan or support-power branch	power light blinks slowly or the machine wakes and collapses	fan branch and support behavior	owner manual and workbook sheet `A100`
Do not open yet branch	the complaint clears on correct polarity, better source, or a heavier external current path	external proof still beats internal teardown	measurement card and parts substitution card

Connector and Board-Family Reminders

Do not treat a weak wall outlet like an internal fault.
Keep current-path and clamp complaints outside the chassis until a known-good path is proven.
Do not open the machine for an improvised TIG complaint because A100 is officially a stick-only platform.
Do not treat wrong DCEN / DCEP lead placement like a board failure.
The workbook split between dead-with-DC and no-OCV-with-DC is the fastest safe internal map on this model.

External Parts Exit Paths

If the opening pass shows the complaint still follows the clamp, holder, or utility-side branch, leave the board path and use the official ordering flow instead.
A100 accessories path: official A100 accessories path
Stock holder KAA20010: official product page
Heavy-duty holder 07000460: official product page
Heavy-duty clamp 07000461: official product page

Stop Rules

Stop if a better clamp or stronger outlet changes the complaint.
Stop if correct polarity and dry 3/32 in proof rod remove the complaint.
Stop if the machine is being evaluated as TIG, because A100 is officially stick-only.
Stop if blinking-light or fan behavior clearly points to the support branch.
Stop and return to the full guide if utility, support, and output evidence still overlap after the first opening pass.

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