{"id":9638,"date":"2025-09-24T11:29:12","date_gmt":"2025-09-24T03:29:12","guid":{"rendered":"https:\/\/www.wehopower.com\/?post_type=news&#038;p=9638"},"modified":"2026-09-02T13:19:29","modified_gmt":"2026-09-02T05:19:29","slug":"top-10-causes-of-power-supply-failures","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/","title":{"rendered":"10 nguy\u00ean nh\u00e2n h\u00e0ng \u0111\u1ea7u g\u00e2y ra l\u1ed7i ngu\u1ed3n \u0111i\u1ec7n"},"content":{"rendered":"<p class=\"weho-last-updated\" style=\"text-align:center;color:#E60013\">Last Updated: 2026-09-02<\/p>\n<blockquote class=\"weho-quick-answer\">\n<p>causes of power supply failures most often involve excessive heat, sustained overload, abnormal input voltage, surges, blocked airflow, contamination, vibration, loose connections, aging components, or a supply that was not matched to the application. Preventive action starts with correct sizing, documented derating, clean installation, secure wiring, surge coordination, and regular inspection under real operating conditions.<\/p>\n<\/blockquote>\n<figure class=\"weho-blog-image weho-blog-hero\"><img fetchpriority=\"high\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/01-hero-9.png?quality=85&strip=all\" alt=\"Preventive maintenance of an industrial control cabinet\" title=\"Preventive maintenance of an industrial control cabinet\" width=\"1536\" height=\"1024\" class=\"alignnone size-full wp-image-17156\" srcset=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/01-hero-9.png?quality=85&strip=all 1536w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/01-hero-9-300x200.png?quality=85&strip=all 300w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/01-hero-9-1024x683.png?quality=85&strip=all 1024w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/01-hero-9-768x512.png?quality=85&strip=all 768w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/01-hero-9-18x12.png?quality=85&strip=all 18w\" sizes=\"(max-width: 1536px) 100vw, 1536px\" \/><\/figure>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#causes_of_power_supply_failures_begin_with_application_conditions\" >causes of power supply failures begin with application conditions<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#1_Excessive_temperature\" >1. Excessive temperature<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#2_Continuous_overload\" >2. Continuous overload<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#3_Abnormal_input_voltage_and_dropouts\" >3. Abnormal input voltage and dropouts<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#4_Surges_and_transients\" >4. Surges and transients<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#5_Blocked_airflow_or_fan_wear\" >5. Blocked airflow or fan wear<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#6_Dust_moisture_and_corrosive_contamination\" >6. Dust, moisture, and corrosive contamination<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#7_Loose_or_damaged_connections\" >7. Loose or damaged connections<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#8_Vibration_and_mechanical_stress\" >8. Vibration and mechanical stress<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#9_Component_aging\" >9. Component aging<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#10_Incorrect_product_or_system_selection\" >10. Incorrect product or system selection<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#Prevention_and_troubleshooting_sequence\" >Prevention and troubleshooting sequence<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#FAQs\" >FAQs<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#What_is_the_most_common_cause_of_power_supply_failure\" >What is the most common cause of power supply failure?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#Can_an_overloaded_power_supply_fail_permanently\" >Can an overloaded power supply fail permanently?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#Do_power_surges_damage_switching_power_supplies\" >Do power surges damage switching power supplies?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#Why_does_a_power_supply_fail_only_when_it_gets_hot\" >Why does a power supply fail only when it gets hot?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#Can_dust_cause_a_power_supply_failure\" >Can dust cause a power supply failure?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#How_can_I_extend_power_supply_service_life\" >How can I extend power supply service life?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#Key_Takeaways\" >Key Takeaways<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/www.wehopower.com\/vi\/news\/top-10-causes-of-power-supply-failures\/#Conclusion\" >Conclusion<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"causes_of_power_supply_failures_begin_with_application_conditions\"><\/span>causes of power supply failures begin with application conditions<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The leading <strong>causes of power supply failures<\/strong> are usually connected to heat, electrical stress, environment, wiring, or incorrect selection rather than one mysterious internal defect. A supply may stop completely, restart repeatedly, produce low voltage, become noisy, or fail only after warming. Each symptom needs a system-level investigation.<\/p>\n<p>Exposed mains terminals and stored energy are hazardous. Isolate and verify the safe condition before inspecting wiring. Qualified personnel should perform live measurements, and internal repair should be limited to authorized facilities with suitable isolation and test equipment.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"1_Excessive_temperature\"><\/span>1. Excessive temperature<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>High temperature accelerates the aging of electrolytic capacitors, insulation, fans, and semiconductor junctions. The relevant temperature is inside the enclosure and near the supply, not only the room temperature. Blocked vents, insufficient spacing, nearby drives, solar gain, and dense cabinet layouts can all raise it.<\/p>\n<p>Apply the manufacturer&#8217;s temperature derating, mounting orientation, and clearance rules. Measure temperature during the worst production cycle and inspect filters and fans on a defined schedule.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"2_Continuous_overload\"><\/span>2. Continuous overload<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure class=\"weho-blog-image\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/02-technical-diagram-9.png?quality=85&strip=all\" alt=\"Power-supply failure prevention loop\" title=\"Power-supply failure prevention loop\" width=\"1536\" height=\"1024\" class=\"alignnone size-full wp-image-17157\" loading=\"lazy\" srcset=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/02-technical-diagram-9.png?quality=85&strip=all 1536w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/02-technical-diagram-9-300x200.png?quality=85&strip=all 300w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/02-technical-diagram-9-1024x683.png?quality=85&strip=all 1024w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/02-technical-diagram-9-768x512.png?quality=85&strip=all 768w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/02-technical-diagram-9-18x12.png?quality=85&strip=all 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><\/figure>\n<p>A load that exceeds rated current increases loss and heat. Current limiting or hiccup protection is a protective response, not a normal operating condition. Repeated cycling stresses the supply and the connected equipment.<\/p>\n<p>Calculate continuous current and short peaks separately. Motors, solenoids, lamps, capacitive loads, and controllers may draw a much higher current during startup. Include ambient and input-voltage derating before deciding that nameplate wattage is sufficient.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"3_Abnormal_input_voltage_and_dropouts\"><\/span>3. Abnormal input voltage and dropouts<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Undervoltage can increase input current or prevent stable startup, while overvoltage can stress input components. Loose contactors, long feeder runs, weak generators, incorrect selector settings, or repeated dropouts may produce an intermittent symptom.<\/p>\n<p>Measure the input during the event rather than only when the system is idle. Confirm frequency and waveform requirements for generator or inverter sources.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"4_Surges_and_transients\"><\/span>4. Surges and transients<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Lightning-induced events, utility switching, contactors, motors, and inductive loads can create transients. Built-in protection has limits. A coordinated system may require upstream surge protective devices, correct grounding, short conductors, and suppression at the disturbance source.<\/p>\n<p>Select protective devices for the actual exposure and applicable standards. A damaged surge component or repeated unexplained fuse operation requires investigation, not automatic replacement.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"5_Blocked_airflow_or_fan_wear\"><\/span>5. Blocked airflow or fan wear<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure class=\"weho-blog-image\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/03-product-9.png?quality=85&strip=all\" alt=\"Real WEHO LRS-150-12 product reference with exact original label\" title=\"Real WEHO LRS-150-12 product reference with exact original label\" width=\"1536\" height=\"1024\" class=\"alignnone size-full wp-image-17158\" loading=\"lazy\" srcset=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/03-product-9.png?quality=85&strip=all 1536w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/03-product-9-300x200.png?quality=85&strip=all 300w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/03-product-9-1024x683.png?quality=85&strip=all 1024w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/03-product-9-768x512.png?quality=85&strip=all 768w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/03-product-9-18x12.png?quality=85&strip=all 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><\/figure>\n<p>Fan-cooled models depend on airflow direction, filter condition, and fan health. A fan may become noisy, slow, or stop as bearings wear. Natural-convection models still require free space around ventilation openings.<\/p>\n<p>Do not bypass thermal protection. Replace fans only with authorized parts and procedures, and recheck temperature under maximum load after service.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"6_Dust_moisture_and_corrosive_contamination\"><\/span>6. Dust, moisture, and corrosive contamination<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Dust reduces heat transfer and can become conductive when mixed with moisture. Oil mist, salt, chemicals, and condensation can corrode terminals and circuit assemblies. Select an enclosure and ingress protection strategy for the environment.<\/p>\n<p>De-energize before cleaning and avoid compressed-air methods that drive contamination deeper into equipment. If internal corrosion is present, use authorized service or replacement.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"7_Loose_or_damaged_connections\"><\/span>7. Loose or damaged connections<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure class=\"weho-blog-image\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/04-installation-9.png?quality=85&strip=all\" alt=\"Real WEHO LRS-150-12 detail sheet using unchanged source pixels\" title=\"Real WEHO LRS-150-12 detail sheet using unchanged source pixels\" width=\"1536\" height=\"1024\" class=\"alignnone size-full wp-image-17159\" loading=\"lazy\" srcset=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/04-installation-9.png?quality=85&strip=all 1536w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/04-installation-9-300x200.png?quality=85&strip=all 300w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/04-installation-9-1024x683.png?quality=85&strip=all 1024w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/04-installation-9-768x512.png?quality=85&strip=all 768w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/04-installation-9-18x12.png?quality=85&strip=all 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><\/figure>\n<p>Incorrect torque, poor crimping, loose strands, vibration, and thermal cycling increase contact resistance. The resulting heat can discolor terminals, melt connectors, reduce output voltage, or cause arcing.<\/p>\n<p>Use specified conductors, ferrules or lugs where required, strain relief, and documented terminal torque. Inspect both positive and return paths because a return fault can create the same symptom as a positive-conductor fault.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"8_Vibration_and_mechanical_stress\"><\/span>8. Vibration and mechanical stress<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Machinery vibration can loosen terminals and fatigue conductors, connectors, solder joints, or heavy components. Unsupported cables transfer force into terminal blocks. Shock during shipping can also damage a supply before commissioning.<\/p>\n<p>Mount on a rigid surface using all required points, support cables, and verify that the model is suitable for the vibration environment. Investigate intermittent faults by recording when vibration and load events occur.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"9_Component_aging\"><\/span>9. Component aging<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Capacitors dry with time and heat, fans wear, relays accumulate operations, and insulation experiences electrical and thermal stress. Aging may first appear as increased ripple, difficult cold start, reduced hold-up, or failure after warm-up.<\/p>\n<p>Trend output voltage, ripple using a correct measurement method, temperature, and fan condition. Replace or service before a critical failure when performance moves outside the documented limit.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"10_Incorrect_product_or_system_selection\"><\/span>10. Incorrect product or system selection<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A supply chosen only by voltage and wattage may be unsuitable for the load&#8217;s startup behavior, ripple tolerance, cooling, input source, mechanical format, environment, or protection coordination. Replacing a failed unit with an identical one will not help if the application cause remains.<\/p>\n<p>Use the <a href=\"https:\/\/www.wehopower.com\/product_category\/enclosed-switching-power-supply\/\">WEHO enclosed switching power supply category<\/a> to compare approved formats and the <a href=\"https:\/\/www.wehopower.com\/product\/150w-ac-dc-switching-power-supply\/\">WEHO LRS-150 page<\/a> as a real product reference. Verify the exact output variant and documentation for the application.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Prevention_and_troubleshooting_sequence\"><\/span>Prevention and troubleshooting sequence<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure class=\"weho-blog-image\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/05-application-9.png?quality=85&strip=all\" alt=\"Industrial power-system preventive maintenance environment\" title=\"Industrial power-system preventive maintenance environment\" width=\"1536\" height=\"1024\" class=\"alignnone size-full wp-image-17160\" loading=\"lazy\" srcset=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/05-application-9.png?quality=85&strip=all 1536w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/05-application-9-300x200.png?quality=85&strip=all 300w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/05-application-9-1024x683.png?quality=85&strip=all 1024w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/05-application-9-768x512.png?quality=85&strip=all 768w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/05-application-9-18x12.png?quality=85&strip=all 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><\/figure>\n<p>Document the input, output, load list, startup current, ambient temperature, mounting, airflow, and fault timing. With power isolated, inspect protection, wiring, polarity, terminal condition, selector settings, contamination, and ventilation. Qualified personnel can then verify input and output under controlled load.<\/p>\n<p>For symptom-by-symptom testing, use the internal guide <a href=\"https:\/\/www.wehopower.com\/news\/power-supply-not-working-troubleshooting-guide\/\">Power Supply Not Working: Troubleshooting Guide<\/a>. It separates the AC source, supply, distribution, and load so the failed part is not assumed in advance.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"FAQs\"><\/span>FAQs<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"weho-visible-faq\">\n<h3><span class=\"ez-toc-section\" id=\"What_is_the_most_common_cause_of_power_supply_failure\"><\/span>What is the most common cause of power supply failure?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Excess heat is a frequent contributor because it accelerates component aging. Heat may come from overload, blocked airflow, high ambient temperature, poor mounting, nearby equipment, or a worn fan.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Can_an_overloaded_power_supply_fail_permanently\"><\/span>Can an overloaded power supply fail permanently?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Yes. Protection may limit or shut down output, but repeated or prolonged overload still raises temperature and stresses components. Correct the load and startup demand rather than relying on protection as an operating mode.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Do_power_surges_damage_switching_power_supplies\"><\/span>Do power surges damage switching power supplies?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Surges beyond the equipment and protection system&#8217;s capability can damage input components or weaken insulation. Coordinate upstream surge protection, grounding, and installation with the site exposure and applicable standards.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Why_does_a_power_supply_fail_only_when_it_gets_hot\"><\/span>Why does a power supply fail only when it gets hot?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Temperature can expose aged capacitors, poor solder joints, loose connections, fan problems, or operation beyond thermal limits. Record voltage, current, temperature, and timing from cold start to failure.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Can_dust_cause_a_power_supply_failure\"><\/span>Can dust cause a power supply failure?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Dust can block airflow and, when conductive or moisture-laden, increase leakage and corrosion risk. Use an appropriate enclosure and maintenance interval; never clean an energized supply.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"How_can_I_extend_power_supply_service_life\"><\/span>How can I extend power supply service life?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Apply documented derating, provide airflow and clearance, control contamination and moisture, secure terminals, coordinate surge protection, avoid repeated overload, and inspect current, voltage, temperature, fans, and connectors periodically.<\/p>\n<\/div>\n<h2><span class=\"ez-toc-section\" id=\"Key_Takeaways\"><\/span>Key Takeaways<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li>The main <strong>causes of power supply failures<\/strong> are heat, overload, input stress, surges, contamination, wiring, vibration, aging, and application mismatch.<\/li>\n<li>Protection modes should not be used as continuous operating states.<\/li>\n<li>Measure input, output, current, and temperature during the failing event.<\/li>\n<li>Correct airflow, conductor, terminal, surge, and enclosure problems before installing a replacement.<\/li>\n<li>Use documented derating for temperature, input voltage, orientation, and load behavior.<\/li>\n<li>Keep a maintenance record so gradual change is visible before a critical failure.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span>Conclusion<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Most <strong>causes of power supply failures<\/strong> can be reduced through correct selection, thermal margin, protected wiring, environmental control, and measured maintenance. When a failure occurs, diagnose the complete power path and correct the application stress before replacing the unit.<\/p>\n<p>Compare formats through the <a href=\"https:\/\/www.wehopower.com\/product_category\/enclosed-switching-power-supply\/\">WEHO enclosed switching power supply category<\/a> and <a href=\"https:\/\/www.wehopower.com\/product\/150w-ac-dc-switching-power-supply\/\">LRS-150 product page<\/a>. For model matching, <a href=\"https:\/\/www.wehopower.com\/contact\/\">contact WEHO<\/a> or email sarayu@chnwh.com with the input source, output requirement, load profile, ambient temperature, enclosure, and fault history.<\/p>\n<div class=\"weho-article-cta\">\n<p>Review the <a href=\"https:\/\/www.wehopower.com\/product_category\/enclosed-switching-power-supply\/\">relevant WEHO product category<\/a>, email <a href=\"mailto:sarayu@chnwh.com\">sarayu@chnwh.com<\/a>, or <a href=\"https:\/\/www.wehopower.com\/contact\/\">contact WEHO<\/a> with the input voltage, output load, ambient temperature, and installation details.<\/p>\n<\/div>\n<p><script type=\"application\/ld+json\" class=\"weho-faq-schema\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"What is the most common cause of power supply failure?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Excess heat is a frequent contributor because it accelerates component aging. Heat may come from overload, blocked airflow, high ambient temperature, poor mounting, nearby equipment, or a worn fan.\"}},{\"@type\":\"Question\",\"name\":\"Can an overloaded power supply fail permanently?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. Protection may limit or shut down output, but repeated or prolonged overload still raises temperature and stresses components. Correct the load and startup demand rather than relying on protection as an operating mode.\"}},{\"@type\":\"Question\",\"name\":\"Do power surges damage switching power supplies?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Surges beyond the equipment and protection system's capability can damage input components or weaken insulation. Coordinate upstream surge protection, grounding, and installation with the site exposure and applicable standards.\"}},{\"@type\":\"Question\",\"name\":\"Why does a power supply fail only when it gets hot?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Temperature can expose aged capacitors, poor solder joints, loose connections, fan problems, or operation beyond thermal limits. Record voltage, current, temperature, and timing from cold start to failure.\"}},{\"@type\":\"Question\",\"name\":\"Can dust cause a power supply failure?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Dust can block airflow and, when conductive or moisture-laden, increase leakage and corrosion risk. 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