Diode identification

[RSton.1]

I have a diode that I am trying to identify. Its markings are:

ST e3

ZTTH (the 'Z' is backward)

112

230

Anybody know what it is and what can be used to replace it?

[RSton.1]

On closer inspection it has a 'G' between the STe3 line and the ZTTH line

ST e3

G

ZTTH (the 'Z' is backward)

112

230

[Enrico Poli]

This one STTH112 ?

[RSton.1]

Could be. I found a schematic for similar UPS (slightly different model) and they had a 1N4003 in the same location on the circuit so I used a 1N4007, which I have plenty to hand, and the unit is now working. The MOSFETs were also shot as was the fuse, the diode was the only component I wasn't sure about.

Some of these UPS have Schottky diodes in the switchmode section and will not run properly with a regular diode so I was worried about that. But upon testing the diode was in the regular diode range so that gave me confidence.

Thanks for that, I'll file the datasheet for next time 🙂