I have a S17 with 3 dead hashboards that gradually dropped out. No warranty, no good-will. For sure its the solder breaking on the chips, tried everything.

This is not recommended, but as a last ditch effort tried to re-flow the hash boards by heating to 385 Deg f for 10 min. Haven't had success. I've heard of people bringing motherboards and GPUs back to life using this technique. Theory is the heat melts and reconnects the broken solder joint.

Maybe something to try before you throw your board in the trash. Not sure if anybody else has tried this with any degree of success.