Komatsu 7835‑16‑2001 is an electronic control unit (ECU) used in the PC300‑7/PC300LC‑7 series of excavators to manage hydraulic and engine functions. Common failure modes for this class of controller include power supply degradation, capacitor failure on the board, shorted I/O lines, and firmware corruption that can trigger “ECU fault” or “over‑temperature” error codes. Begin diagnostics by verifying the 24 V DC input voltage and checking for any blown fuses or tripped breakers; inspect the board for burn marks, cracked solder joints, or swollen electrolytic capacitors; then review the diagnostic log for specific fault codes (e.g., 0xA3, 0xB4) that indicate I/O channel failures or communication errors with the hydraulic module.[oss-gpt-20b]