There may be several reasons for the failure of Reed Relays, including:

Magnetic failure: The spring of the reed relay may be damaged or worn, resulting in loss of attraction or rebound force.

Pollution: Dust, grease, or other pollutants may enter the spring gap of the relay, affecting its operation.

Connection issue: The connection wire of the relay may be loose or disconnected, causing the signal to be unable to be transmitted.

Electromagnetic interference: External electromagnetic interference may interfere with the normal operation of the relay.

To conduct accurate failure analysis, it is necessary to carefully inspect the appearance and internal components of the reed relay, eliminate possible problems, and make necessary repairs or replacements. It is best to have professional technicians diagnose and repair.