Board reference · ZX7 / WS
ZX7 / WS long-strip control board reference
Use this page when a ZX7 / WS style inverter stick/TIG welder uses a long narrow control board with feedback, current control, thrust adjustment, protection lamp, thermal switch, 24V supply and driver connectors. The purpose is to identify the board functions and follow the evidence path before replacing the control board.
Board role map
The long-strip control board is the interface between the front-panel command, current feedback, thermal/protection input, driver board and power stage. It may look like a small low-voltage board, but a wrong signal here can shut down the whole inverter.
Connector and adjustment reference
| Function | What it usually does | Symptom when wrong |
|---|---|---|
| Feedback line | Returns output-current or output-voltage evidence to the control loop. | Weak output, false protection, no current regulation or unstable arc. |
| Current potentiometer | Sets welding current command from the front panel. | Current cannot adjust, jumps, or remains at minimum/maximum. |
| Thrust / arc-force potentiometer | Changes stick-welding dynamic response and short-circuit recovery. | Arc sticks, excessive spatter, harsh output or no visible effect. |
| Maximum-current trim | Sets upper current calibration range. | Machine cannot reach rated current or over-current protection appears too early. |
| Thermal switch | Reports heatsink or transformer over-temperature condition. | Protection lamp on, no output, or intermittent shutdown after warm-up. |
| Protection lamp | Visible output of protection/shutdown logic. | Lamp on with no output; lamp off does not always prove drive is present. |
| 24V supply | Feeds control logic, relays, interface circuits or local regulation. | Dead control board, missing drive enable, no relay activity. |
| Driver connector | Carries PWM or drive-enable signal toward the driver board. | Auxiliary rails look normal but IGBT/MOSFET gates receive no valid drive. |
Do not replace the long-strip board first
Check the auxiliary supply, front-panel potentiometers, thermal switch state, feedback line and driver connector before condemning the control board. A shorted output diode, bad driver board or broken feedback connector can make the control board look faulty.