A friend brought me a defective motor system by which the motor was variably driven and in the circuit was a triac. It was open. Upon close inspection there is what appears to be a tvs transient voltage suppresion device in series with the gate! It's about impossible to get any identification info off the device but the pc board has a double diode symbol which looks like two diodes facing each other with a common cathode bar. The other end of the "diode" goes to a capacitor and a relay contact. There is a 3 ohm resistor that is open and a blown npn transistor also.
I've looked allot for any circuit where a tvs is in series with a componant but could not find any. Does anyone know why this type of device would be in series with a part like this?
If it is truly not a tvs, then maybe the pc board silkscreen is wrong and this is just an open diode, with its cathode connected to that gate.
What's the consensus about this?