MP 5,1 upgraded to pair X5690, fans running high

Hi there. I have a refurbished Mac Pro 5,1 (mid-2010). I just recently grabbed a pair of Xeon X5690 SLBVX 3.46GHz chips and had a friend install them. Since the install, my fans have been running full-tilt - resetting the SMC and PRAM has no effect, and I took off the heatsinks to make sure nothing had disconnected or obstructed their thermal sensors. The machine also does not chime when it starts up.

I took the machine in for a diagnostic and just received it back; the tech said that "the...

MP 5,1 upgraded to pair X5690, fans running high