Ask HN: Where can I read about warranty policies between OEM/ VAR?

Hi! I am interested in what are the warranty policies (in general) between OEM / VAR partners in electronics.

Example - Intel/AMD & HP. If the HP finds out that one of their products fails b/c of an Intel/AMD processor failure what happens between the companies?

a) In case of systemic failure (above N% - and what can be N here?)? b) In case of non-systemic failure?

Would that be much different if it's some OEM smartphone + VAR brand? I am implying that OEM smartphone is a more complete package than just MCU (as above).