Having again opened up the Modu82+ for my own failure analysis (it's out of warranty) I have found a clear culprit. A component labelled 'THR1' which I believe to be a thermistor has blown quite catastrophically. All that is left is charred debris scattered throughout the PSU. I have no idea what the spec was as it is that clearly destroyed and the only thing that tells me it's a thermal resistor is looking for the gap where a char mark is left. When it went off it may also have damaged the Diode (D8) right beside it.

I've ordered a Seasonic X-400 as a replacement but am wondering about investigating a fix for this one, if only as a spare to shuffle down in older computers. I would need a spec for a replacement thermistor to use so if anyone has ideas or wants a Modu82+ for spares/repair, let me know.

Had this psu and the chattering fan problem like others. Emailed Enermax about replacement fan and no response. Suffice to say my next PSU isn't an Enermax and doesn't use a cheap, proprietary fan.

Funny, I've had the same chirping sound with my Modu82+ 425W for the last year or so, only just now thought to look it up to see if I could fix (as I put it into a new system), and find so many with the exact same issue. Very frustrating since it was incredibly silent when new.

Ok, my Enermax Modu82+ (EMD425AWT II) has the same problem... Never, ever am I buying another Enermax product!

What a fool I've been, to not research the issue of whether the fan was freely interchangeable. On the other hand, who would have thought they would use some weird proprietary fan?!

What a nonsense, it's not such a real issue: it's enough to just drive the replacement fan externally, through any controllable header.

They have a valid point. The PSU fan runs between around 500-2000rpm. There's no way you are able to use this control for any other fan. Another controllable fan header is going to be no use at all as it won't be based off the PSU temperature. You'd either end up spinning the fan too fast and therefore making too much noise or have the PSU overheating.

IME it is only a theoretical alternative: during the last seven years I've run several PSU fans that way, silently and reliably, never overheating the PSU itself.