R2000F vs. diode

[bigdrums925]

Hi, I'm working on a Bulgera XL333 guitar amp that blows the main fuse when powered up. When I removed wires between the power supply and the EL34 tube board, I could see the current draw was not excessive as it was before. Not too many parts on this board but started by checking the diodes. There are three of them, or so I thought. D4 is actually a R2000F fast recovery rectifier that looks like a diode. I measure .051 ohm in the diode mode either direction. I'd like to know if this is normal.

Tried to attach a schematic and the item is on page 2 near the EL34 tubes.

[Leo_Gnardo]

D4 is actually a R2000F fast recovery rectifier that looks like a diode. I measure .051 ohm in the diode mode either direction. I'd like to know if this is normal.

Sure looks like a shorted part to me. Diodes conduct in one direction, and not in the other. Yours is far from normal. I'd recommend replacement without a doubt.

[Enzo]

Remove teh two fast recovery diodes from that board, now does the amp work?

[Mick Bailey]

Reading ohms in diode test mode seems unusual. What meter are you using?

[Enzo]

I would suspect it was 0.051 volts, which means the part is shorted. Darn few meters can read 0.051 ohms.

[Leo_Gnardo]

I would suspect it was 0.051 volts, which means the part is shorted. Darn few meters can read 0.051 ohms.

Any way, it looks like that fast recovery diode is now a never recovery diode.

[R.G.]

Actually, a Darkness Emitting Diode (or DED).