[FIXED] Logitech Computer Speaker System Z313: schottky diode failure

[sorenkir]

Hi all,

I have fixed this system recently.
The culprit was a schottky rectifying diode in the secondary part of the 12V SMPS.
In fact there are two diodes in parallel (!), one was completly shorted. These SB5100 schottky diodes are rated 100V 5A.
This failure does not seem uncommon: I have found the exact same description in TerraHertz's blog.

I wonder what kind of failure mode can affect such big diodes in a small speaker system (25W output power) ?

Michel.

[Len]

I can't answer your question, but Big Clive just posted a video showing the same problem. Last lines: "The diodes always fail in these power supplies. It's such a common fault."