2771

Common Causes

• Mechanical obstruction or misalignment preventing the pallet from clamping
• Faulty clamp confirmation or unclamp confirmation limit switch
• Faulty clamp or unclamp solenoid valve
• Loss of hydraulic/air pressure to the clamp circuit

Troubleshooting Steps

1. 1Note the hexadecimal machine diagnosis number shown in the character string and check it in the machine diagnosis data to see which confirmation input is missing.
2. 2Inspect the pallet and table locating surfaces for chips or debris that would block mechanical seating, clean them, and retry the pallet change.
3. 3Verify the clamp and unclamp solenoid valves energize (listen/feel for actuation) and that hydraulic or air pressure is present at the clamp circuit.
4. 4Check operation of the clamp confirmation and unclamp confirmation limit switches; confirm their inputs change state in the I/O diagnosis screen as the pallet clamps and unclamps.
5. 5Replace the faulty limit switch or solenoid identified above; if clamping is mechanically impossible, record the alarm number and diagnosis number and contact Okuma service.