@Framiga:
I would just like to make something clear about my solution. The original small phase 5 fan attracts dust if it's turned on and working. I didn't meant that it attracts dust just by sitting there regardless of it being turned on or off. :-)
If that fan is turned on and spinning, the heatsink on the other side provides a perfect cover for any dust that's sucked in by the fan to stay there, in the area of the 603e chip. That's why I suggested unplugging that fan from receiving power. The dust build-up around the 603e can eventually kill it.
You will not notice any dust problems right away, but it will slowly build up in 6 months or so.
This is a very tricky task...to properly cool the entire BPPC weak spots. :-)