The rrod was pretty well know for a long time. Video games are sold to kids so it had the requirement to not use lead solder in them even though lead solder is

The rrod was pretty well know for a long time. Video games are sold to kids so it had the requirement to not use lead solder in them even though lead solder is perfectly safe and no way a child would be exposed to it, unless they eat the xbox. Lead solder is much softer so with the countless hot cold cycles, when hot the solder expands and when cold it contracts, it will handle these cycles much much better. Without the lead the solder joints are not as soft and the hot and cold cycles eventually results in the solder joints cracking and no longer making a solid connection = rrod. Some models were more prone to rrod but the biggest trick is to make sure you do regular cleaning and dusting to keep air flow working. Don't put the xbox in a cabinet with no air flow where it will heat up. Put a fan on the xbox if you can. It has been a long time since I followed the xbox scene but there are tons of posts online about the entire problem and best practices to avoid it.