I stripped the m9700 down to the bare motherboard and chassis. Cleaned every component and the motherboard with cotton swaps with 91% rubbing alcohol.
Reseated everything, new AS5 thermal grease applied, reassembled.
In the meantime, I did a ton of reading about 'solid amber' power lights.
Seems the solid amber is related to CPU. Either the CPU, CPU fan, or CPU not getting power.
All 3 of those will result in a solid amber power light.
So now I have...