So I got a great deal on a Brower Top Hatch THI30 that I found on Craigslist, and I'm planning to use it for a hatcher. I just set it up and everything seems to be in order, except I can't find where I'm supposed to adjust the temp? There seems to be what looks like a screw in the side of the base, but no knob or anything that looks adjustable. So far it is holding around 100 degrees but I'm afraid to put eggs in it without knowing in advance how to make adjustments if I need to. I did buy this used (it is brand new but because I'm not the original owner I'm thinking it's just missing a part) I just can't figure out if this is actually the case, have looked through the directions (online) and pics and am still mystified. Also, is the light supposed to flash on and off intermittently? Like it will stay on for a few seconds, then go off, come back on for a few seconds, etc etc. Any help would be greatly appreciated!!