When the screen gets stuck here, it means the bootloader cannot complete its self-test or load the necessary system files. Understanding why this happens and knowing how to troubleshoot it can save you thousands of dollars in unnecessary board replacements and minimize machine downtime. 1. Primary Causes of the Boot Freeze
Make it a strict policy to back up your SRAM data to a dedicated CompactFlash card or network drive every six months, and always before making any parameter changes.
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.
Regularly back up your SRAM, FROM, and parameter files to a PCMCIA CompactFlash card or USB drive. fanuc starting system software please wait
However, the remaining 15%—involving failed FROM chips, cracked solder joints on the main CPU, or dead boot blocks—requires professional FANUC repair. Authorized service centers (like FANUC itself, or third-party repair firms such as CNC Specialty Store or Industrial Control Repair) can re-flash boot prom, replace surface-mount SRAM chips, or emulate failed modules.
Most FANUC controls have an hidden Initial Program Loader (IPL) menu. To access it:
In rare cases, a short on a remote I/O unit (ex: FANUC I/O Link, Profibus, or DeviceNet) can feed noise back into the backplane bus. During system software initialization, the CNC polls connected devices. If a device does not respond correctly, the boot process waits indefinitely. When the screen gets stuck here, it means
No backup? Do not perform this step. Instead, call a FANUC repair service that can dump the SRAM via the Boot Monitor's serial port.
FANUC controllers use flash ROM (FROM) to store system software and SRAM to store parameters and programs. If these physical modules degrade, or if the main master PCB board suffers an electronic failure, the system cannot read the required boot files. 3. Faulty Memory Card or Peripherals
If the message never progresses and hardware checks out, the . Primary Causes of the Boot Freeze Make it
If the power supply is stable, find out if an optional hardware component is blocking the system bus. Turn off the control.
Clean the gold edge connectors of the cards with an electronic contact cleaner.
Locate the two rightmost softkeys beneath the CNC display screen (often labeled or corresponding to the right-pointing arrow keys). On older monitors or small screens, press and hold the and . keys on the alphanumeric keypad simultaneously.
Store copies on two different media (CF card + network drive).