Welding machine

C0121S00 Circuit Board PCB Genuine Spare Part for OTC DAIHEN

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OTC DAIHEN C0121S (C0121S00) Driver Board – Genuine for AVP360 / AVP500 TIG Welders

This page showcases the OTC DAIHEN C0121S / C0121S00 driver board, a genuine spare part used in AVP series TIG welding machines, including the AVP360 and AVP500 models. This board is clearly marked with DAIHEN OTC and PART NO. C0121S. It is a critical component that drives the inverter and is often damaged simultaneously when the IGBT fails. Below you will find photos, specifications, and ordering information.

OTC DAIHEN C0121S genuine driver board for AVP series TIG welders

Product Overview

The C0121S (C0121S00) is a genuine OTC DAIHEN driver board designed for the AVP series TIG (argon arc) welding machines, specifically the AVP360 and AVP500. It serves as the interface and control board for the inverter section, providing gate drive signals to the IGBTs. Based on field maintenance experience, when an IGBT fails (often accompanied by a loud "pop" sound and machine shutdown), this driver board is frequently damaged as well, and sometimes the fuse also blows. Replacing both the IGBT and the driver board is recommended to ensure reliable operation.

OTC DAIHEN C0121S00 driver board component side view

Specifications

Part Numbers: C0121S / C0121S00
Description: Driver board for TIG welding machine
Applicable Welders: OTC DAIHEN AVP360, AVP500 and compatible AVP series TIG welders
Markings: DAIHEN OTC, PART NO. C0121S
Common Failure Note: Often damaged when IGBT fails (explodes)
Origin: Japan – genuine OTC DAIHEN production

Why Choose Genuine OTC DAIHEN Driver Boards?

Using authentic OTC DAIHEN C0121S driver boards ensures correct drive signals, proper protection circuitry, and long‑term reliability. Non‑OEM boards may have incorrect component values, leading to repeated IGBT failures or erratic welder behavior. As an authorized OTC DAIHEN distributor, we supply only 100% original, factory‑sealed parts.