Inoperative Bulb mode

Symptome

An inoperative or inconsistent Bulb / B mode often comes with other signs, such as all speeds appearing to run at once or intermittent behavior after rest.

Contextes

Treat it as a clue within a disturbed sequence cycle rather than as a fully isolated fault.

Causes a envisager

General causes of an incoherent cycle: power supply, contacts, capacitors, sequence reset, or incomplete mechanical return.

Checks utiles

• Return to the central incoherent cycle across multiple speeds entry
• Test Bulb before and after power-supply or mechanical-return work
• Cross-check with the other symptoms present

Heuristique

The keyword Bulb is mainly a search entry: in practice, a wider incoherent cycle often has to be diagnosed.