CPU Hardware Failure

Summary

CPU hardware failure covers processors that prevent POST, trigger machine-check or CATERR events, drop cores, or crash reliably under load. In this set, CPU faults often surface indirectly first as boot codes, DRAM symptoms, board suspicion, or unstable mixed CPU-memory paths.

Frequency

• 93 tickets mention CPU-led hardware failure or a CPU path later confirmed during diagnosis or RMA.

Common Causes

1. Defective CPU silicon causing POST failure, Q-codes, or no-boot states. Seen as Q-code 00/90/97/98, no video, GRUB/POST hangs, or CPUs that fail only in one socket. (#22223, #23751, #7793, #20849, #3971, and 20+ more)
2. Machine Check, CATERR, or core-level processor faults under workload. These appear as MCE logs, CATERR1/IERR, corrected or uncorrectable CPU events, segfaults, or crashes during CPU-heavy jobs. (#11944, #23066, #24185, #31455, #5509, and 15+ more)
3. CPU-side memory path failures. Some cases initially look like DIMM or training errors, but CPU swap logic or later depot testing points to the processor or its socket path. (#29865, #29887, #35216, #35896, #16883, and 10+ more)
4. Socket or motherboard damage presenting as a CPU fault. Bent pins, thermal paste contamination, damaged sockets, or board-level faults can mimic a bad CPU until depot inspection isolates the real failure path. (#19426, #8369, #19931, #19937, #18150, and 10+ more)
5. Thermal or power-regulation failures around the CPU path. A smaller group involves overheating, cooler failure, burned CPU VRM areas, or shutdowns that ultimately trace to CPU-adjacent hardware. (#37229, #3354, #24794, #38665 is related context outside this set, #34598)

Diagnostic Steps

1. Check for CPU-coded boot evidence first. Capture Q-codes, CATERR/MCE logs, BIOS code behavior, missing cores, and whether the system reaches POST, GRUB, or OS at all. (#22223, #20167, #36638, #7793)
2. Use swap logic to separate CPU from DIMM, GPU, and board faults. Move CPUs between sockets or systems when safe, reduce DIMM population, and see whether the failure follows the processor. (#23751, #29887, #4453, #22302, #32859)
3. Inspect the CPU path physically. Check socket pins, paste contamination, cooler seating, power delivery areas, and whether shipping damage or incomplete returns are hiding the real fault. (#19426, #3354, #19931, #37855)
4. Stress the repaired or suspect system before closure. CPU-heavy jobs, burn-in, or customer workload reproduction often surface latent faults missed by static bench checks. (#14669, #25082, #28266, #37229, #40743)

Solutions

1. Replace the faulty CPU. This is the clearest successful fix when swap testing or logs isolate the processor. (#14669, #22223, #23751, #3971, #9063, and 25+ more)
2. Repair or replace the motherboard / socket path when CPU symptoms are secondary. Many no-boot CPU cases are resolved only after board repair, socket repair, or full barebone replacement. (#19426, #18150, #19931, #19937, #8369, and 20+ more)
3. Return the full system for depot diagnosis when field isolation is incomplete. This works best for mixed CPU, memory, BMC, and boot-path failures. (#20849, #28036, #28051, #34201, #34686, and 20+ more)
4. Apply firmware or BIOS remediation only as a ruling-out step, not as the main fix. BIOS, BMC, or microcode updates sometimes help isolate the path, but successful closure usually still required hardware repair or replacement. (#35666, #32135, #28266, #40743)
5. Correct adjacent components when they are the true cause. A minority of CPU-looking cases were ultimately fixed by HBA, motherboard, PSU, or non-CPU component replacement. (#19426, #28445, #30954, #8756)

Edge Cases

• Repeat RMA after partial success. Some systems passed initial repair, then failed again under customer workload or after return. (#24241, #25082, #30309, #36753)
• CPU fault mixed with shipping or return-handling issues. Incomplete returns, transit damage, or damaged parts complicated diagnosis. (#19931, #19937, #37855, #8369)
• CPU-only part RMAs with thin technical detail. A number of component tickets clearly involve faulty CPUs but preserve mostly logistics rather than diagnostics. (#20567, #20948, #27584, #28588, #36332)
• Software-looking symptom that proved hardware. Browser crashes, SEV-SNP enablement failures, memory training faults, and OS boot hangs sometimes ended in CPU-path replacement. (#28445, #32135, #29865, #19937)

Related Issues

• System Boot Failure
• Motherboard Hardware Failure
• Memory Hardware Failure
• BIOS BMC Issues
• CPU Cooler Failure

Referenced by

• RTX 5090 — product affected by this issue (×2)
• Motherboard Hardware Failure — co-occurs with this issue (×22)
• Jason Chen — handled tickets on this issue (×21)
• Sheng Ye — handled tickets on this issue (×2)
• Shipping Damage — co-occurs with this issue (×4)
• System Boot Failure — co-occurs with this issue (×25)
• Ian Dicarlo — handled tickets on this issue (×17)
• Memory Hardware Failure — co-occurs with this issue (×5)
• TS4-194492555 — product affected by this issue (×1)
• RMA Workflow — co-occurs with this issue (×79)