Fanuc Starting System Software Please Wait -

Decoding the "FANUC Starting System Software Please Wait" Message: Causes, Fixes, and Prevention

3. Common Causes of a "Please Wait" Hang

If the system stays on "Please Wait" indefinitely:

4. Hardware Hang – Main CPU Board or Peripheral Conflict

Less common but more severe: the main processor (often a 32-bit RISC chip like the FANUC I/O Link processor) enters an undefined state.

• Broken servo amplifier feedback: If the CNC initializes the FSSB before completing the system software load (a rare sequence bug), a failed servo drive board on the I/O link can cause a deadlock.
• Faulty flush-mount CF card or USB drive: Some FANUC models (31i-B, 0i-D) check removable media during boot. A corrupted USB stick inserted in the front port can stall the loader.

2.3 Faulty Main CPU Board or Memory Module

Physical hardware failure is less common but does occur. Electrolytic capacitors on older FANUC 16/18/21 series main boards (circa 1995–2005) degrade over time, causing unstable voltage rails. Also, the "Master PCB" or "Main CPU Board" (e.g., A16B-3200-xxxx) can develop cracked solder joints on the DRAM chips.