Testing a VN05N

[cs.dk]

Is it possible to test a VN05N for any damage, either in circuit or as a standalone component? Datasheet here: http://pdf.datasheetcatalog.com/datasheet/SGSThomsonMicroelectronics/mXuqvut.pdf

Reason is, that many Citroen Xantia and XM uses these transistors to activate soft suspension-mode, but because of flyback from the coil/solenoid they break down over time. I've got new VN05N's and some 1N5822 diodes, so I should be able to fix the ECU's i've got. But it would be nice to know if the VN05's in the ECU actually is dead, before just replacing them on a row..

[SeanB]

Diode test between drain and source, along with the same between gate and source. If there is any short circuit or leakage just change it. Forward voltage should be in the same ballpark as a regular silicon diode on the meter, reverse should be open circuit with the load disconnected. Gate may show some due to the driver, but check on each side of any gate resistor to see that at the driver side the voltage will be slightly lower.