2 Apple Service Diagnostics errors, is it CPU or Logicboard?

Hi

because my Mac Pro 3.1 (Early 2008) sometimes does not wake up fully after sleep mode I decided to test it with Apple Service Diagnostic. It gave me 2 errors which I don't know how to interpret.

1)

- Current (ICBC) - CPU-B core current (test 1)

- Sensor Reads Within Operating Range

- Check to ensure that sensor reads within operating range.

ERROR - 3 Sensor reading below low point - (1.61)

TEST FAILED

2)

Thermal Interface - Processor ProcessorB (test 4)

- TIM Test 75 percent Gardband

- Check that CPU heatsink is properly attached

using product spec theta dh + 75 percent guardband.

ERROR -47006 Processor power error - TEST FAILED

I would be glad if someone has an idea.

Thanks in advance.