Yup, it is doing exactly as you described.
After few hours it does not properly boot. ( not showing any video on hdmi, and network is not active). Its actually just like firmware corruption.
Interesting, I just tested yesterday if its on, its stays on whit out any issues for hours....
So, according to my experience, it can be two things...
- weak/blown capacitator...(I checked them all visually, not one is damaged or swollen).
- bad/broken ROM(flash) chip.
Third...far possibility is generally weak/unstable external PSU.
This possibility I plan to eliminate latter today with brand new PSU.
If this doesn't help....than its one of the upper mentioned issues.
thank for the patience...