Trying to identify SOT89 transistor with SMD marking

Thread Starter


Joined Aug 28, 2017
I am trying to identify this component which I believe it is a transistor.
It is inside a speedometer from a vehicle which works with 12 Volt power supply.
I am 100% sure it is size SOT89 and the SMD marking are AL S75
Check photo to see where are the SMD markings on the component.
In your opinion what is the real part number of this component ?

I have searched on the internet for this SMD marking and I found part number ZXTN19055DZTA transistor.
Mouser had in stock and I bought a few. These are NPN 20V transistor.
These arrived today. The SMD marking is S75. I tested on the speedometer and it does not work.
If I install used parts AL S75 from other speedometer it works fine.

Is anyone able to help ?

Many thanks !!!