I have a component on my D5 EVO electric gate motor PCB which was shorting both ends to GND. This resulted in the PCB not powering on.

After removing this component the PCB now powers on, but part of the logic responsible for peripherals does not work. I'm hoping a replacement of this part of equivalent will fix the peripheral side.

The component looks like a diode, and when testing other chips of the same kind they show a voltage across them like a diode but there are no polarity markings.

Scouring the internet seems to show no results for the markings FBL Z803 however I think the brand name for the component is ST

I hope the part is not a Chinese mystery chip copy or something similar. Does anyone have any suggestions or has anyone come across this type of component?

Perhaps someone could also give tips on searching for parts in a situation like this.

Part in question FBL Z803

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1x orange resettable fuse and 2x 100 Ω resistors. Could be current sensing for the MCU.

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1 Answer 1


Appears to be a SMCJ18CA, 18V transient voltage suppressor diode (TVS).

The diode sacrificed itself to protect the rest of the circuitry from an overvoltage event.

ST's datasheet for the diode lists the markings in the ordering information section, with "FBL" corresponding to the 18V version.


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