Cordless vacuum will not power on when main switch is set to ON and battery is installed

Safety first: Remove the battery pack from the vacuum before any inspection. Do not work on the tool while it is connected to a charger.

• 1. Verify battery and contacts: Test the Festool battery pack in another Festool cordless tool. If it works there, inspect the vacuum's battery terminals for bent pins, corrosion, or debris. Clean gently with a dry brush and compressed air.
• 2. Check main power switch: Move the main switch between OFF and ON several times. If it feels loose, gritty, or does not click positively, the switch may be defective. Remove the housing screws (using the correct Torx driver) and carefully separate the housing halves to visually inspect the switch and its spade connectors.
• 3. Inspect wiring harness: Look for broken, pinched, or burned wires between the battery terminal block, main switch, and control electronics module. Reseat any loose connectors firmly.
• 4. Examine control electronics module: Check the control PCB for obvious burn marks or damaged components. If visible damage is present, the module should be replaced as a complete assembly rather than repaired at component level.
• 5. Reassemble and test: Refit the housing, install the battery, and test. If the unit still shows E01 and will not power on, discontinue use and contact an authorized Festool service center, as further diagnosis requires specialized test equipment.