Help identifying Mosfet on Xantrex 500, 12 to 220Vac Inverter

[carbono.silicio]

Hello All,

Bought a Xantrex 500, 12Vdc do 220Vac Inverter on a local flea market but it doesn't work. Took out 4 Mosfet's of one side and with the diode test between drain and source after touching momentarily on the gate, all of them show 0,017V and the DMM beep's continuously, instead of the normal 0.7V diode forward voltage.

I presume these Mosfet's are bad but the ID markings are erased as pictures below show.

Does anyone have a clue of witch ones might be? or similar one's?

Thank you very much.

[technogeeky]

I found this link for decoding "3rd generation" mosfets from IR.

My best guess given the picture was IRF247 or IRFZ47 (IRFZ makes sense given manufacturer and package, and IRFZ4 is allowed but evidently IRFZ47 is not).

Good luck!

[macboy]

Hello All,

Bought a Xantrex 500, 12Vdc do 220Vac Inverter on a local flea market but it doesn't work. Took out 4 Mosfet's of one side and with the diode test between drain and source after touching momentarily on the gate, all of them show 0,017V and the DMM beep's continuously, instead of the normal 0.7V diode forward voltage.

That is expected. You should not get a diode drop across drain-source of a MOSFET that is turned on. There is not a PN junction between drain and source, as there is in a BJT between collector and emitter.  A fully-on MOSFET should have a low resistance between D and S (See R_DSon).