Your nose is a diagnostic instrument. Burning smells and heat signs are the two symptoms that outrank every other — one means unplug now, the other explains half of all mystery slowness.
Most symptoms let you finish your work first. Smell does not. A burning, acrid or sharp chemical smell from a computer means something is getting hot enough to damage insulation or components, and the correct response is always the same first step: switch off and unplug. Only after that do you diagnose. Heat is the smell's quieter partner — it rarely announces itself directly, so it hides behind throttling, fan noise and shutdowns. This guide covers both: which smells point where, and how to prove overheating with numbers instead of guesses.
👆 Example symptom map. Smell plus heat together always outrank speed — safety first, diagnosis second.
The commonest source of a burning smell is the power supply: it handles mains voltage, its components age, and when one fails it often cooks. A PSU that smells burnt is finished — it is replaced, never opened (its capacitors can hold a dangerous charge long after unplugging) and never kept in service because it still happens to work. After unplugging:
One honest exception: a brand-new PC or PSU can give a faint warm-electronics smell for the first day or two. Faint and fading is normal; strong, sharp or growing is not.
Overheating shows itself in behaviour before it shows in smoke. The classic pattern is a PC that is fast when cold and slow when warm — the processor protects itself by throttling its speed, so a machine that crawls after twenty minutes of work but flies after a night off is describing its own temperature problem. Other readable signs: fans roaring during light tasks, the area around the CPU vent too hot to rest a hand on, shutdowns that happen during games or summer afternoons but never in the morning, and laptops that only misbehave on a bed or lap where vents are blocked. Each sign narrows the cooling chain: intake, heatsink, fan, paste, exhaust — one of them is failing.
Suspicion is not measurement. A free temperature tool (HWiNFO or your board maker's utility) turns the argument into numbers:
Numbers also protect you from false repairs: if temperatures are normal, the slowdown lives somewhere else, and re-pasting would have fixed nothing.
Cooling faults are mechanical, so the fix order is physical and cheap-first:
After each step, re-measure. The temperature drop is your proof, and it tells you which step was the real fault.
See the overheating signs on real machines in the video — where the smell comes from, how the dust builds up, and the cleaning done properly.
▶️ Watch Full VideoA faint warm-electronics smell in the first day or two of a new machine is usually manufacturing residue and fades. Worry when the smell is sharp or acrid, grows stronger, or comes with heat, noise or shutdowns — then unplug and investigate.
Very often, yes — gaming is the heaviest heat load, and shutdown is the processor's last protection. Prove it by watching temperatures during a game; if they climb to the limit right before the shutdown, cooling is the fault. A weak power supply is the second suspect if temperatures stay normal.
Indirectly, yes. Dust insulates the heatsink, temperatures rise, and the processor throttles its own speed to survive. The slowdown is real even though the dust never touched a single file — cleaning restores the speed the throttling took away.