Dewalt DWMT70779 Instruction Manual - Page 10

English TROUBLESHOOTING GUIDE This section provides a list of the more frequently encountered malfunctions, their cause and corrective actions. The operator or maintenance personnel can perform some corrective actions, and others may require the assistance of a qualified DeWALT technician or your dealer. Defective Pattern Likely cause Suggested Remedy Heavy top or bottom pattern Split pattern 1. Dirty or damaged air cap 2. Dirty or damaged fluid tip Air pressure too high for material viscosity being sprayed. 1. Dirty or distorted air horn holes. 2. One of the air horn holes completely obstructed. 1. Rotate air cap 180°. If the pattern follows the air cap, the problem is in the air cap. Clean and inspect the air cap. If the pattern is not corrected, replacement is necessary. 2. If pattern doesn't follow the air cap, the problem is with the fluid tip. Clean and inspect the tip for dried paint, dirt or damage. If the pattern is not corrected, replacement is necessary. 1. Reduce air pressure. 2. Turn pattern control knob clockwise to decrease fan width. Turn fluid needle adjusting nut counterclockwise to increase fluid flow. 1. Rotate air cap 180°. If the pattern follows the air cap, the problem is in the air cap. 2. Clean and inspect the horn holes. If the horn holes are distorted, replacement is necessary. Gun splitting Air getting into paint stream somewhere. Example: Same symptoms as a cup running out paint. 1. Check and tighten fluid needle packing nut. 2. Tighten fluid tip. 3. Check fluid tip seat for damage. 4. Check for poor gun to cup seating. 5. Check that cup is correctly fastened on the gun. Defective Pattern Likely cause Suggested Remedy Spitting, irregular or fluttering spray Air back pressuring into cup. Unatomized or spattered spray Inadequate air delivery 1. Fluid nozzle cracked or worn 2. Leak at thread of fluid nozzle 3. Leak at fluid needle 4. Needle packing worn out 5. Insufficient fluid in cup 6. Vent hole in container cover clogged Excessive air blowing back into cup. 1. Material too heavy 2. Insufficient air pressure 3. Fluid pressure too high 4. Dried material on tip of fluid nozzle or air jets of air cap 1. Air needle partially closed 2. Dried material in air jets or air cap 3. Obstruction in air line 1. Tighten or replace 2. Tighten fluid nozzle 3. Tighten compression nut assembly or replace needle packing 4. Replace packing 5. Fill cup with fluid 6. Clean out 1. Tighten fluid tip. 2. Check fluid tip seat. 3. Check for damaged fluid seat on tip or seat on gun head. 1. Thin material or use larger orifice fluid nozzle set 2. Increase pressure to within limit 3. Reduce pressure 4. Clean 1. Open control knob 2. Clean 3. Remove obstruction Excessive fog 1. Air pressure too high 1. Reduce air pressure and/or for viscosity of fluid open fluid control knob 10