Display shows E7 when the solution trigger is pressed; no spray and audible click from handle but no pump action.

Safety first: Unplug the machine before opening the handle or body.

• Inspect handle and trigger: Check that the trigger moves freely and returns under spring tension. Look for cracks or physical damage.
• Open handle housing: Remove screws securing the handle halves. Carefully separate them to expose the trigger microswitch and wiring.
• Test microswitch: With a multimeter on continuity, press the trigger and verify the switch opens and closes correctly. Replace the switch if it does not change state reliably.
• Check handle loom: Inspect the cable running from the handle down to the main body. Look for kinks, cuts, or crushed sections, especially where it flexes.
• Reseat connectors: Ensure the handle loom connector is fully engaged in the main body socket and free of corrosion.
• Reassemble and test: Refit the handle, ensuring no wires are pinched. Plug in and test. If E7 persists, the input circuit on the main PCB may be faulty.