OK, I cloned that repository, but I'm running into the same problem as before. Also, I didn't mention that setting frequency with --gekko-compacf-freq <value> does not actually change the frequency. The frequency remains the default one (200). I wouldn't rather buy a fan at the moment. I would like to have it working without a fan, even if that means I should lower the frequency, I have no problem with that.
If you're going to run it without a fan, you'll need to upgrade the heatsink and thermal compound. The stock heatsink isn't good enough for just passive cooling
I typically use a start command like this, it uses the tune algorithm to ramp up the clock rate to the target frequency
./cgminer -o stratum+tcp://solo.ckpool.org:3333 -u YOURBTCADDRESS -p x --gekko-compacf-freq 545 --gekko-start-freq 400 --gekko-mine2 --gekko-tune2 60 --suggest-diff 1000