I own five Chromecast units generations 1 thru 3. Whenever my unit would start resetting itself during use, I would replaced it with a new unit.
I always thought that the units ran too hot since they were always hot to the touch.
Recently I started to have a lot of system interruptions while streaming video in the evenings. Over a number of months I began eliminating elements of my video system in order to isolate the cause of the problem. Eventually the failure was isolated to the Chromecast dongle. It would reset itself several times per evening, giving the distinctive "G" on the screen.
I Googled "Chromecast over- heat" and discovered that others have the same problem.
Solution: I ordered two heat sinks - the metal heat radiators used to cool the processor chips in PCs and desktops. I attached the sticky sides of the heat sinks, one to each side of the dongle.
It has been several weeks now and the Chromecast unit has only reset itself once.
