X-Can V2 Cooling
| I've just finished "cooling"
this unit which has been left powered up for the past 4 years. These babies
run warm (especially if you live in a warm climate) and the points to watch
for are the transistors scorching the PCB and the caps drying out. This
doesn't happen overnight but you can imagine what heat the components are
subjected to if the unit is left on for years.
1: Drill holes in the PSU board. This will allow
the heat to transfer up and away from the transistors (make sure you don't
drill through any of the tracks, there is plenty of free board to drill
but be careful!):
2: Fit suitable heatsinks onto the transistors. You
will get heatsinks on the two that require heatsinks, namely the two located
under the PSU board, you will have to saw the fins off one side of the
sinks so they don't "touch" each other... if they touch you'll
get a very big "bang" so make sure there is a gap between them.
The best heatsinks for this application are from RS components, Part number:
507-4753 36p each. Perfect size but, as mentioned, you'll have to cut
the fins off one of them in order that they don't both make contact. The
scorching is Perfectly Normal and you'll also find, if you turn the board
over, there's the likelihood the tranny pads have lifted off the board
due to the heat...... easy to reinforce just scrape back the green from
the tracks to expose the copper and then solder on the copper which will
reinforce the transistor connections, it's worth doing this "anyway"
as the solder will help dissipate the heat from the transistors.
3: If you're a paranoid android then you can also
vent the enclosure itself, this is not totally necessary as the heatsinks
and drilled PSU board will help transfer heat away from the transistors
but if you live in an extremely warm climate then enclosure ventilation
may also be prudent:
4: Replace all of the 85C caps with high temperature
105C types, these are better suited to this application: