Question

Difficulty: MediumCPU Architecture Cooling and Sockets

A desktop technician upgrades a high-performance workstation CPU to a processor with a 125W Thermal Design Power (TDP). Shortly after powering on under heavy processing loads, the workstation suddenly powers off without displaying a stop error. Hardware diagnostic software recorded CPU core temperatures rapidly spiking above 100°C before the system shut down. Upon visual inspection, the technician observes that the active cooling fan is spinning normally and thermal compound was applied to the processor surface. Which of the following is the most likely cause of this thermal throttling and shutdown issue?

  1. The protective plastic peel-off film on the bottom of the heatsink copper base plate was left attached prior to mounting.Answer
  2. B
    The power supply unit wattage capacity is insufficient for the peak power consumption of the new processor.
  3. C
    The motherboard BIOS requires a firmware flash to support multi-core hyperthreading processor instructions.
  4. D
    The processor was installed with incorrect pin orientation inside the Zero Insertion Force (ZIF) motherboard socket.

Answer

The protective plastic peel-off film on the bottom of the heatsink copper base plate was left attached prior to mounting.
The correct answer identifies that leaving the manufacturer's protective plastic film on the bottom of the heatsink creates a thermal insulator. Even with working fans and thermal compound, heat cannot conduct into the heatsink fins, resulting in rapid thermal throttling and system protection thermal shutdown.

Step-by-Step Solution

1
Analyze the reported thermal symptoms and environment.
The fan spins and thermal paste is applied, yet thermal runaway (exceeding 100°C) causes a sudden thermal protection shutdown under load.
Excessive heat accumulation despite active fan operation indicates heat is not conducting from the CPU die into the cooling fins.
2
Evaluate heat transfer mechanics between CPU heat spreader and thermal heatsink base.
Identified physical thermal barrier between CPU surface and heatsink plate.
New heatsinks often ship with a transparent protective plastic sticker covering the copper base. If not removed, plastic acts as a thermal insulator.

Key Concept

CPU Thermal Management and Heatsink Installation
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