# Troubleshooting overview

The table below describes common problems, possible reasons and requiered actions.

Start any kind of troubleshooting by checking supply pressure. Reference value: 5-7 bar.

Problems | Possible reasons | Actions
--- | --- | ---
Tool starts immediately when air hose is connected. | Motor valve defective / stuck in open position. | Replace the motor valve.
| Air logic unit defective. | Replace the air logic unit.
Motor runs, but spindle does not rotate. | Split gear, planetary gear, bevel gear or gear wheel in motor housing defective. | Preparation: Remove the motor valve and motor from the head. Spin the input shaft of the gear.
|  | If the spindle rotates and the gears runs smooth: 1) Make sure the gear wheel in motor housing is OK. 2) Remove the motor from housing and make sure outgoing gear is OK. 3) Low speed unit: If the primary gear is OK, make sure the planetary gear is OK. 4) High speed unit: Make sure the splines adapter and gear / splines are OK.
|  | If the spindle does not rotate and the gears hacks and sheaves: 1) Remove the split gear. 2) Rotate one axle and hold against the other. If the split gears condition are OK: 3) Remove the bevel gears from bevel gear housing. 4) Make sure the bevel gears condition are OK.
|  | If the bevel gears are OK, the gear wheels in the head are broken.
Spindle rotates, but does not feed forward. | Air logic unit defective. | If clicking noise from the spindle: The spindle is probably stuck in home position, if not make sure feed gear is OK. Remove the spindle, see section Changing the spindle. Perform a test. Service is needed if the spindle stucks again. Test that spindle rotates.
| Feed gear problem. | Make sure the declutching moment is correct, pls contact your Atlas Copco representative for instruction.
| Air logic unit defective. | Replace the air logic unit.
Spindle stops or feed back before drilling cycle is completed. | Drill bit defective. | Replace the drill bit.
| Too low declutching moment in overload clutch. | Make sure the declutching moment is correct, pls contact your Atlas Copco representative for instruction.
| Too high drill force. Too large drill size. | Verify rpm / feed / drill size according to specifications.
Motor stops before end position. | Air leak in valve pin in upper housing. | Replace the valve pin.
| O-ring missing or defective. | Make sure all o-rings in upper housing are OK. Replace if necessary.
| Motor valve defective in upper housing. | Replace the motor valve.
Spindle does not feed back when drilled finished. | Valve pin defective. | Replace the valve pin.
| Valve pin blocked. | Verify that the valve pin are free and not blocked from grease and dirt.
| Air logic unit defective. | Replace the air logic unit.
| Rocker valve defective. | Replace the rocker valve.
Spindle does not feed back when rettract-button is activated. | Air logic unit defective. | Replace the air logic unit.
Tool does not start when start button is activated. | Too low supply pressure. | Make sure the supply pressure is correct, see section Technical data.
| Emergency stop activated. | Pull the emergency stop button to reset it.
| Air leak in valve pins in upper housing. | Make sure no air leaks exists.
| Motor valve defective. | Replace the motor valve.
| Air logic unit defective. | Replace the air logic unit.
| Air leak in joints, caused of defective or missing o-rings. | Make sure the o-rings condition are OK.
| Motor valve blocked. | Verify that the valve is free.
| Rocker valve defective. | Replace the rocker valve.
Tool starts slowly when start button is activated. | O-ring in motor valve are not lubricated. | For instruction, see section Lubrication.
Motor starts, but stops immediately when start button is released. | Overload clutch stuck in open position. | Make sure the overload clutch functions properly.
| Air leak in valve pins. | Replace the overload clutch.
| Air logic unit defective. | Replace the air logic unit.
Motor does not stop in home position or runs “unnecessary long time” before stoping. | Rocker valve defective. | Replace the rocker valve.
| Valve pin defective. | Replace the valve pin in upper housing.
| Motor valve closing too slow. | Replace the motor valve.
| Stop in valve pin. | Verify that valve pin in upper housing is free and not blocked.
Incorrect spindle speed. Reference value: +/- 10% from rated speed. | Motor defective. | Replace the motor.
| Split gear reversed. | Make sure the split gears spec. are correct and that right side is up.
| Wrong split gear. | Verify that correct split gear is selected.
Tool starts and feeds forward when start button is pushed down, but retract when start button is released. | Air leak in overload clutch valve pin. | Make sure that all o-rings are in good condition. Replace the overload clutch.
Tool starts but retract when start button is released. | Air leak in overload clutch. | Replace the overload clutch.