Fanuc Starting System Software Please Wait !!hot!! Jun 2026

Look for a digital status display (a single-digit LED) or a row of status LEDs on the master board. A normal boot displays a sequence changing rapidly.

If the controller remains stuck, you must enter the Boot Monitor to run diagnostics or re-initialize the system.

So, why does it get stuck? Based on common field reports and repair logs, the causes typically fall into a few key areas.

During startup, the system copies software from the FROM into the Dynamic RAM (DRAM) for execution. If the DRAM chips or the main CPU board experience hardware degradation, the data transfer fails, causing the bootloader to lock up. Peripheral Card and Option Slot Interference fanuc starting system software please wait

Unplug Ethernet cables and serial RS-232 communication lines.

to allow all capacitors in the control and drives to fully discharge.

FANUC stores system software on a memory module (often called the "FROM" or Flash ROM). If a critical sector becomes corrupted due to a sudden power loss during a previous write operation, the boot loop hangs. This is especially common if the machine was powered off while a parameter write or a macro compilation was in progress. Look for a digital status display (a single-digit

If possible, verify if any I/O units are showing error lights. 3. Perform a Cold Start (Initialization)

Or, in some older models: "FANUC BOOT SYSTEM SOFTWARE PLEASE WAIT."

What is the of your FANUC control (e.g., 0i-MC, 18i-TB, 31i)? So, why does it get stuck

The fanuc controller is too hot, causing the CPU to throttle or fail to initialize correctly. Troubleshooting Steps (Step-by-Step)

A peripheral device (e.g., a peripheral card, tool changer, or robot arm) is not responding, stalling the initialization of the overall system.

Loose components caused by machine vibrations can break connections. Power down the machine and lock out the electrical cabinet.