The main enemy for most electronics is heat. Older 5V PS2 boards tend to run pretty warm anyway, and this can cause premature failures. Capacitor explosions and other burnout issues are common problems. This is perhaps not so much of a problem on a smaller home layout with short run sessions, but it can be a serious issue on a larger club or modular layout scenario, especially if you are pulling large consists for long sessions. So anything we can do to keep them cooler is liable to help with the longevity of these somewhat fragile boards.
To help with cooling I bought a 4-pack of small 25m x 7mm computer-type 5V cooling fans, cheap on Amazon. They are the perfect size to be mounted up under the roof of most any diesel, exhausting upwards through one of the roof cooling fan outlets, fittingly. They are only 7mm thick so they fit inside most any diesel shell, positioned right over the board stack to effectively draw cool air up through the boards. This is especially effective if the boards are vertically mounted. They glue up against the roof easily using something like Goo; a small dab on each of the 4 corners.
PS2-5V boards maintain the 5 volt regulator chip active and powered anytime there is track power present. The TO-220 device is remote mounted off the board, usually fastened with a machine screw to the engine frame for heat sinking. This makes it easily accessible for connection, and avoids any modification of the boards themselves. The supplied fan power wire comes with a JST-XH 2-pin female connector, which mates nicely with a pre-wired 2-pin XH header plug, for connection to the Vreg plug. It can also be re-wired with a JST micro 1.25 M/F pigtail which is more compact than the XH series. The connections are fan black to Vreg black, and fan red to Vreg yellow (not red).
The fan runs anytime there is track power, but power consumption is only 150 ma, so the load impact on the electronics is minimal. This can be handy if the engine is parked on live track after a running session; the fan will continue to run and cool things down. Make no mistake this little fan is not going to blow your hat off or anything. But within the confined space of an O scale engine it moves lots of air. The published sound level is only 26 db; almost unnoticeable.
Pretty easy mod and only takes about an hour to complete. The first one I did is a Premier F3 lead A unit. The shell internals are pretty crowded in F units with the 5V boards and a smoke unit stuffed in there. The fan is mounted under the twin screened louvres right behind the cab, which puts it conveniently right over the front end of the board stack. After 15-20 minutes run time you can definitely notice the warmer air being exhausted by the fan. And the plastic engine shell is noticeably cooler with the fan running. So far I've done two F3's and an SD-40; all PS2-5V and working fine. It’s a win for sure. Some installation pictures below:
Rod
