Obsolete & Hard-to-Find Capacitors

Every year, manufacturers discontinue capacitor product lines as they shift focus to newer technologies. But industrial equipment, military systems, medical devices, and legacy electronics can remain in service for decades longer than the components inside them. When a critical capacitor fails in a 20-year-old UPS system, a vintage aerospace unit, or a legacy motor drive, finding an exact replacement becomes a mission-critical challenge.

Specap has been solving this exact problem since 1984. As one of America's leading obsolete capacitor distributors, we maintain an extensive warehouse of NOS (New Old Stock) capacitors and access a global network of legacy component suppliers. Whether you need a discontinued Sprague Atom electrolytic, a legacy Mallory motor capacitor, a rare Aerovox film capacitor, or an Allen-Bradley industrial component, our team has the sourcing expertise to locate it.

Our engineering cross-reference service goes beyond simple part matching. When an exact obsolete capacitor is truly unavailable, our engineers analyze the original specifications — capacitance, voltage, ESR, ripple current, temperature rating, and physical dimensions — to identify a modern equivalent that meets or exceeds the original performance. This service has saved countless machines from the scrapyard and kept critical systems operational.

Based on four decades of customer requests, these are the obsolete capacitor types we source most frequently:

• •Computer-grade screw terminal electrolytic capacitors — DC bus capacitors for VFDs, motor drives, UPS systems, and industrial power supplies. These large-can capacitors are often custom values made for specific equipment and become obsolete when production runs end.
• •Allen-Bradley drive capacitors — Capacitors for legacy Allen-Bradley PowerFlex, 1336, 1305, and 1397 series drives. These industrial automation systems run for decades, but original capacitors fail after 7-15 years.
• •Motor start and run capacitors — Obsolete motor capacitors for discontinued HVAC equipment, commercial refrigeration, and industrial motors with specific form factors no longer in production.
• •MIL-spec and aerospace capacitors — Military-specification tantalum, mica, and film capacitors for defense and aerospace platforms that remain in service for 30-40+ years.
• •Medical device capacitors — Replacement capacitors for legacy medical equipment including imaging systems, patient monitors, and therapeutic devices where regulatory compliance requires exact component matching.
• •UPS and power supply capacitors — DC link and filter capacitors for legacy UPS systems from APC, Eaton, Liebert, Exide, Best Power, and other brands where original parts are no longer manufactured.

Have excess or surplus capacitors sitting in your warehouse? Specap purchases excess capacitor inventory — including obsolete, overstock, and end-of-line capacitors from distributors, manufacturers, and OEMs. Your surplus inventory becomes a lifeline for another customer searching for a discontinued part. We offer competitive pricing and handle all logistics. Learn more about selling your excess capacitor inventory to Specap →

Finding a reliable source for obsolete capacitors is the biggest challenge facing maintenance engineers and repair technicians. Unlike commodity components available from any distributor, obsolete capacitors require a specialist with deep industry connections, extensive warehouse inventory, and the technical knowledge to identify suitable replacements.

Specap is America's premier obsolete capacitor distributor. Our 40+ years in the capacitor business gives us advantages that newer or general-purpose distributors simply cannot match: relationships with legacy component stockpiles worldwide, a warehouse of NOS (New Old Stock) inventory maintained under proper storage conditions, and engineers who understand vintage capacitor specifications and can identify safe modern substitutes.

Don't risk your equipment with untested surplus. All obsolete capacitors from Specap are inspected and, when necessary, electrically reformed and tested before shipping. Electrolytic capacitors that have been stored for extended periods can develop increased leakage current — our reformation process restores the oxide layer and ensures the capacitor meets its original specifications.

Have excess or surplus capacitors you no longer need? We also buy excess inventory and surplus capacitors — turning your unused stock into cash while helping other customers find the parts they need.