The fact is, for CPU, the biggest problem in space is not cold

but how to dissipate the heat. Most novice people heard about space is that the temperature is 3K. That is true, the microwave background radiation is about 3K. However, most people don't understand vacuum is perhaps the best insulator. That's what keeps your coffee warm. There is almost no air, even there is air inside the satellite, there is 0-g meaning that there is no convection. Radiation at CPU working temperature doesn't cool down the CPU effectively. It takes a lot of effort to get ride of the heat from any electronic components. As for Sun light, again, since there is no air, the shield of the satellite gets hot, but the shield doesn't usually directly connect to electronic components, heat won't conduct easily.

(I hate the char limit on title)