Model family · WS TIG board stack
WS-200P / WS-200S TIG welder board stack
Use this page to understand how WS-200P and WS-200S TIG welders divide the machine into bottom-board relay/gas/HF control, upper-board drive and feedback, middle-board output/rectifier section and HF arc-start section. It is a repair map for no gas, no HF, no arc, protection and weak-output faults.
Board roles
Bottom board
24V/control supply, hand-switch input, relay power, gas-valve relay, power relay, fan, silicon bridge and HF control interface.
Upper board
Current feedback, current potentiometer, pulse adjustment, thermal switch, protection lamp, DC bus and MOSFET/gate-drive area.
Middle board
Main transformer connector, current-voltage feedback, secondary rectifier, shunt/divider path and HF-control connector.
HF start section
HF relay, boost transformer, discharge resistor, high-voltage silicon parts, HF cable connector and gas/HF timing interface.
Repair sequence map
WS-200P vs WS-200S notes
| Area | WS-200P emphasis | WS-200S emphasis |
|---|---|---|
| Bottom board | AC36V, 24V control, relay supply, gas-valve relay, startup relay and hand/TIG switching. | DC380V bus, main filter capacitors, HF section, gas delay components, fan and AC220V gas valve. |
| Upper board | DC308V supply, current pot, pulse adjustment, thermal switch, protection lamp and MOSFET/output section. | Feedback socket, DC24V blocking control, output power transformer, gate resistors, power MOSFETs and board-to-middle-board connection. |
| Middle board | Current-voltage feedback, main transformer plug, shunt, HF control connector and secondary rectifier. | Main transformer, current-voltage feedback, arc-start tube, HF control wire connector and secondary rectifier tubes. |
| Gas / post-flow | Bottom-board relay sequence should be verified before replacing HF or upper board. | Delay capacitors and post-flow conversion path can affect gas after-flow timing. |
Use board roles before replacing parts
If the complaint is “no arc,” first decide whether the fault is no gas, no HF, no inverter output or no arc transfer. A healthy HF board cannot create output if the upper-board drive is blocked, and a healthy upper board cannot open the gas valve if bottom-board relay logic is missing.