Common Electronic Component Failures (And How to Avoid Them)

Common Electronic Component Failures (And How to Avoid Them)

Most electronics don’t fail because “the part was bad.” They fail because parts are stressed in ways the BOM didn’t anticipate: heat, spikes, ESD, moisture, vibration, inrush, poor layout, or wrong substitutions.

This post covers the most common component failures you’ll see in real products—and what to do during design and sourcing to prevent them.

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1) Overvoltage damage (regulators, ICs, MOSFETs die instantly)

What it looks like
• Device won’t power on
• Regulator is shorted
• IC pin is burned or the chip runs hot immediately

Common causes
• Wrong adapter plugged in
• Inductive spikes on long wires
• Automotive/industrial transients
• No surge protection at power entry

How to prevent it
• Add TVS diode at power input (correct working voltage)
• Use input protection (reverse polarity MOSFET, fuse/PPTC)
• Add MOV for mains AC designs (where appropriate)
• Choose components with voltage margin (don’t rate exactly at Vin)

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2) ESD failures (ports die or “become weird” later)

What it looks like
• USB/HDMI stops working
• Touch events cause resets
• Product works but becomes unreliable after field use

Common causes
• No ESD TVS on external connectors
• TVS placed far from the connector
• Long/weak ground return path for the TVS
• Poor connector shell grounding strategy

How to prevent it
• Place low-cap ESD TVS at the connector pins
• Keep TVS-to-ground path short and wide (multiple vias)
• Control return paths and shield bonding

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3) Thermal overstress (silent killer)

What it looks like
• Works at first, fails after hours/days
• Random resets under load
• Discoloration or delamination near hot parts
• Electrolytic capacitors bulge/dry out early

Common causes
• LDO used with big Vin–Vout drop at high current
• MOSFET chosen by Id only (Rds(on) too high)
• Poor PCB copper for heat spreading
• Hot enclosure with no airflow

How to prevent it
• Do thermal math early:
• LDO loss: (Vin − Vout) × I
• MOSFET loss: I² × Rds(on)
• Use switching regulators when needed
• Choose bigger packages and add copper area/thermal vias
• Keep electrolytics away from hot zones

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4) Inductive kickback (kills transistors and causes resets)

What it looks like
• MOSFET/BJT dies near relay/motor
• MCU resets when relay switches
• EMI spikes and unstable behavior

Common causes
• No flyback diode for DC coils
• No snubber/MOV for AC loads
• Long wiring harness increases spikes

How to prevent it
• DC coils: flyback diode or TVS clamp
• AC loads: RC snubber and/or MOV (depending on design)
• Separate power routing for high-current loads vs MCU rail

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5) Capacitor problems (ripple, resets, “it works in lab only”)

What it looks like
• Power rail ripple too high
• Buck converter unstable
• MCU resets during radio transmit or motor start
• Noise in ADC readings

Common causes
• Using MLCC bulk caps with low voltage rating (DC bias reduces capacitance)
• Wrong ESR range for a regulator
• Caps placed far from IC pins
• Poor ground return paths

How to prevent it
• Follow regulator datasheet recommended cap types/values first
• Use proper voltage margin for MLCC (often 2× is safer)
• Place decoupling close to IC pins with short ground paths
• Add bulk capacitance near step-load sources (radio, motor driver)

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6) Connector and solder joint failures (intermittent, hardest to debug)

What it looks like
• Random resets when cable moves
• Works only in certain positions
• Field returns with “no fault found” at factory

Common causes
• No strain relief
• No locking connector in vibration environment
• SMD connector used where mechanical stress is high
• Poor PCB support or weak solder fillets

How to prevent it
• Use locking connectors for vibration
• Use through-hole or reinforced connectors for external ports
• Add strain relief and enclosure support
• Avoid placing connectors on flexing PCB edges

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7) EMI coupling and layout issues (mystery noise and failures)

What it looks like
• Fails EMC testing
• Noise on ADC or audio
• Communication errors on cables
• Unstable switching regulators

Common causes
• Big switching “hot loop” in DC-DC converter layout
• Long return paths and broken ground reference
• Sensitive traces routed near switch nodes
• Poor shielding/connector grounding

How to prevent it
• Copy reference layouts for power converters
• Keep switch node small and isolated
• Maintain continuous ground plane return paths
• Add filtering at board edges and connector boundaries

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8) Incorrect substitutions (BOM changes that break reliability)

What it looks like
• Same design, different batch behaves differently
• Increased failure rate after supply-chain changes
• “Only some units fail”

Common causes
• Replacing MLCC with different dielectric/voltage/package (capacitance changes under bias)
• Substituting MOSFET with higher Rds(on) or higher Qg
• Replacing inductor with lower Isat
• Using “equivalent” TVS with wrong capacitance or clamping

How to prevent it
• Control AVL carefully (approved vendor list)
• Specify critical parameters in BOM notes:
• MLCC dielectric + voltage rating + package
• inductor Isat and DCR
• MOSFET Rds(on) at your gate voltage and Qg
• TVS capacitance and IEC rating
• Validate substitutions with quick bench tests

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9) Counterfeit components (the sourcing risk)

What it looks like
• Parts fail early or don’t meet spec
• Markings look suspicious
• Performance varies wildly between lots

Common causes
• Grey market sourcing during shortages
• Unverified brokers
• Too-good-to-be-true pricing

How to prevent it
• Prefer authorized distributors
• Use traceability requirements for critical parts
• Incoming inspection for high-risk components
• Avoid “mystery” parts for safety-critical designs

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10) Moisture, corrosion, and contamination (slow failures)

What it looks like
• Failures after months in humid environments
• Leakage currents, corrosion, green/white residue
• Buttons/contacts become intermittent

Common causes
• No conformal coating where needed
• Wrong connector plating
• Flux residue and poor cleaning
• Enclosure allows condensation

How to prevent it
• Choose gold plating for sensitive connectors in humid areas
• Consider conformal coating if environment is harsh
• Improve cleaning and process control
• Design enclosure to avoid water traps and condensation

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Quick “prevent failures” checklist (useful for every design)

Before production, ask:
• Do we have protection at power input (reverse, surge, ESD)?
• Are inductive loads properly clamped (diode/snubber/MOV)?
• Are thermal losses calculated and heatsinking/copper adequate?
• Are decoupling caps placed correctly and sized with margin?
• Are connectors mechanically supported and locked if needed?
• Are critical BOM parameters controlled for substitutions?
• Are sourcing channels reliable and traceable?
• Is layout following best practices for switching and high-speed?