I have 2 identical Alpine amps, one has a blown (part of it blown off) SMD diode, I can make out UF 42 on it. Odd that the other identical board I was going to use the part off of has several of them by the power mosfets (irfs) but they are all UF 51. I guess they changed up the circuit? I cant find an ID for this SMD online. Any IDEAS what SMD diode UF 42 or UF 51 is and if they would be interchangeable?


I replaced the two shorted Irfs (power mosfets) and fired it up and it blew the 7.5 amp fuse on my PS and blew the two mosfets I just replaced. After using a 30x magnifying glass I found this bad diode by the mosfets and hopeful this is the short blowing the mosfets.

Any help IDing that SMD would be much appreciated.

 

There are several ways to do this.
1) I can't find a reference to the SMD codes starting with, "UF".
2) I can't look up the model of the amplifiers because you did not provide it.
3) I think you have worse problems than shattered diodes.

 

Hello,

The only code with UF I could find is for a BB801 varicap diode, but that is likely not used in that circuit.
http://info.electronicwerkstatt.de/bereiche/bauteile/smd/smd_aktiv/u.html

Bertus

 

There are several ways to do this.
1) I can't find a reference to the SMD codes starting with, "UF".
2) I can't look up the model of the amplifiers because you did not provide it.
3) I think you have worse problems than shattered diodes.

Model of the amp is Alpine MRV-M500 Mono V-Power Digital Amplifier. When I got it it had two blown fets in the PS, I replace them and it blew them again, I still had the shorted (overlooked) diode in that circuit which contributed to blowing them again. First step is getting that diode replaced and replacing the new blown set of fets, could be more issues of course.