MOD wrote: My understanding is that RROD issues are at least partly related to the low melting point of the lead-free solder they are required to use for safety/environmental purposes. If they'd been able to use real leaded solder the melting temp might have been high enough to withstand the temps the system subjects it to. So they've been working on bringing operating temps down to the threshold of the crappy solder.
To give a little perspective to my post, I spent 5 years in the Marine Corps as a specialist in circuit board repair and component replacement. So when I say there is absolutely no reason for a device to be designed in such a way that it could melt the solder joints from its own heat, I have some frame of reference. We ran our stations at 650 just to be able to heat the contact, component lead and solder well enough to induce flow. Below 500 our solder would never melt period. This is the tin/lead combination. I'm not entirely sure what's going on, but my guess would be more along the lines of faulty components, ie. barely in spec as opposed to exactly correct. or something along those lines. Also cooling, as with the very tiny descrete components you find on most computer circuitry, they're very suceptable to heat damage, especially if that heat is very high for long periods of time.
from wiki
Tin/lead solders, also called soft solders, are commercially available with tin concentrations between 5% and 70% by weight. The greater the tin concentration, the greater the solder’s tensile and shear strengths. At the retail level, the two most common alloys are 60/40 Sn/Pb which melts at 370 °F or 188 °C and 63/37 Sn/Pb used principally in electrical work. The 63/37 ratio is notable in that it is a eutectic mixture, which means:
1. It has the lowest melting point (183 °C or 361.4 °F) of all the tin/lead alloys; and 2. The melting point is truly a point — not a range
As a matter of fact, only three of the 15 lead free solder formula's listed have a melting point lower than that of the standard tin/lead formula.
http://en.wikipedia.org/wiki/Solder