The 30 day warranty has been printed on every manual for years. The occasional failures are well known at this point.

You should take responsibility. You assumed the risk when you purchased the table.

What is your rationale for it being someone else’s responsibility?

Those seem like good points to base a discussion around. I appreciate your willingness to explain your reasoning, I find that very helpful.

In my mind, everything has an expected failure rate. Obviously if MINE has failed that's bad for me, the question is 'what is normal'. No individual can answer that. Gathering data at scale might do it. It's hard to compare the failure rate of this component on this node board. Is it specific to this application? This position in the Spike architecture? Bad lot of chips? Sub-optimal component choice during the design?

The chip melting doesn't concern me much because that's an expected result from an internal short. When a chip fails open nothing happens but it stops working. If it fails closed that circuit heats up until it melts the short and goes open. Hopefully that will be before it catches anything else on fire.

Stern has the schematic available but it looks like a later revision maybe? 72D vs your 72B
https://sternpinball.com/support/ scroll to the bottom where all the Spike schematics are located.