OK , final test results.
After letting it alone with the attract mode screen saver running.
10:23 AM 74.1C
The genesis console was sitting on the floor, with carpet underneath.
I decided to set it on a hard back book, to allow air to circulate under the case. (Pads on bottom should raise case about 1/8 inch off surface).
10:30 AM 75.2C
10:45 AM 72.0 C
Surprisingly, it didnt seem to make any difference if the air slots on bottom were covered or not. I sat the case back on carpet.
11:15 AM 71.4 C
Well, I guess thats it for now, unless I see some unusual behavior later.
What did I learn?
I will not waste money on the cheap "stick on" heatsinks.
My next project I will use a "real" heat sink with silicone heatsink compound.
Will probably mount heatsink in a similar fashion, unless I come up with something better. Probably wont use the hotglue for this, I can see where it could be a mess if it gets hot enough for the glue to run.)
Here is my rig, with a Gigaware USB controller:
I shut it down and pull top cover off, while glue was warm the blobs came off pretty easy. Glue was soft but not to the point of becoming liquid like it was yesterday.
Maybe the paper clip wire pressed the heatsink down closer to the cpu when the glue softened, allowing better heat transfer? I dont know.