X32 Rack, Road worthiness issue

Brian jojade

Senior
Jan 15, 2011
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Wausau, WI
www.happymacshop.com
I was re-mounting an X32 rack for a show, and when I pulled the unit out, I noticed there was a rattle inside. This seemed odd, so I opened it up and found a metal clip floating around inside the unit. After a little investigation, I found that the clip is what holds transistors to the heat sink on the power supply. Normally, you would see a transistor screwed to the heat sink. In this case, it's a metal clip that's just pressed over the transistor to hold it to the heat sink. In an install scenario, it's not a big deal, but for something on the road, in a small case that may not be oriented vertically all the time, the chance of these clips falling off exists.

If the clip falls off, there are 2 problems. First, the clip could short something out. Second, the transistor that the clip fell off from may now overheat and result in complete failure of the unit. The mixer in question is only a couple months old, and hasn't been used much, so this was quite the surprise to find.
 
Re: X32 Rack, Road worthiness issue

Normally, you would see a transistor screwed to the heat sink. In this case, it's a metal clip that's just pressed over the transistor to hold it to the heat sink.

These days mostly clips are used, the advantage is that it has a constant force on the transistor.
Also for mains connected components, often the creepage / clearance is not enough when a screw is used.

(But clips can also be screw mounted to the housing...)
 
Re: X32 Rack, Road worthiness issue

Interesting. This is the first time I've seen them in use. I was surprised how loose the clips seemed to be. Not loose enough to just fall off on their own, but loose enough that I could see them vibrating away, especially if the unit was transported on its side or upside down.

This could have been just a manufacturing snafu and it was never on correctly from the factory. Who knows. I'm tempted to put a drop of silicone on it just to make sure.