Microsoft has admitted the severity of the RROD epidemic and allocated 1 billion dollars to fix it, but they still refuse to disclose neither the number of affected consoles nor the cause of the problem.
Japanese tech magazine Nikkei Electronics took it upon themselves to find out. The magazine hired a "Thermal Design Expert" to have a look at a 2 years old Xbox 360 console and assess it thermal design features.
In a nutshell, the expert found out that the heat sinks were too small and the fan too slow.
The expert found that Xbox 360 exhaust air was 22 degrees higher than ambient room temperature, opposed to consumer electronics standards which should keep that difference within 10 degrees. The fan was also found to have a maximum air speed one half to one third that of an average desktop PC, though given the 360's smaller size, the amount of air movement was only considered "slightly in short".
The thermal design expert then opened the case and commented that "the heat sink on the graphics LSI is so small, I wonder if it can really cool down the board". The Japanese magazine suggested that the undersized heat sink might have been used to allow space for the DVD drive.
The expert found that after five minutes play, the graphics heat sink rose to 70 C, and then to 80 C ten minutes after that. Interestingly, the microprocessor's sink leveled out at 58 C. During summer, the report suggests, the graphics LSI could hit 100 C or more.
Finally, the Japanese expert took a look at another Xbox 360 machine that has been repaired by Microsoft after dying by RROD; and he discovered that other than replacing the faulty parts, nothing was done to prevent the problem from happening again.