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Expert Services

Industrial Power Supply (SMPS) Repair

Component-level repair for high-reliability switching and linear power supplies.

Service Overview

Power supplies (SMPS) are the entry point for electrical energy in control cabinets. Because they directly handle high grid voltages, they are frequently damaged by spikes, lightning, and thermal overload. When a power supply fails, the entire cabinet goes dark. Usha Engineering Services specializes in rebuilding industrial PSUs. We replace switching transistors, PWM control ICs, rectifiers, and high-frequency transformers to restore stable voltage rails.

Supported Hardware Series & Models:

Mean Well (HDR, LRS, NDR Series)

Siemens Sitop (Power Supplies)

Phoenix Contact (Quint Power)

Omron (S8VK Series)

Puls (Dimension Series)

Lambda

Custom Machine SMPS Modules

Common Failure Modes & Diagnostic Codes

Technical Reference Sheet for Engineers

Code / Symptom	Probable Cause	Engineering Remedy
Blown Input Fuse (Short Circuit)	Shorted input bridge rectifier, failed MOV surge protector, or shorted MOSFET/IGBT switch	Test rectifier bridge, desolder shorted switching transistor, inspect gate drive circuit, and replace the fuse.
Voltage Ripple / Noise on Output	Dried-out output filtering capacitors with high ESR (Equivalent Series Resistance)	Measure output ripple with oscilloscope. Desolder degraded capacitors and install new low-ESR, high-temperature units.
No Output / Clicking Sound	PSU is stuck in hiccup mode due to output overload, shorted rectifier diode, or feedback loop failure	Test output diodes for shorts, replace optocouplers (e.g. PC817), and check the TL431 voltage regulator reference IC.
Intermittent Output Drop	Thermal stress weakening solder joints on high-temperature components (transformers, power resistors)	Clean board, locate dry joints under microscope, and resolder connections with high-grade leaded solder.

Our Premium 6-Step Component-Level Repair Process

How we restore electronic components to manufacturer specifications

Incoming Visual & Thermal Inspection

Every unit is registered and subjected to high-definition visual inspection and thermal scanning. We identify blown trace lines, scorched resistors, swollen capacitors, and signs of liquid ingress before applying any power.

In-Circuit Analog Signature Analysis

Using advanced Tracker/Signature Analyzers (such as Huntron Trackers), we test passive components (resistors, diodes, capacitors, inductors) and active ICs while in-circuit. This safe, power-off testing compares component electrical signatures against known-good standards.

Semiconductor Power-Stage Diagnostics

For VFDs and servo drives, we test the high-power rectifier and IGBT inverter stages. We check the gate-drive circuit paths, desaturation protections, and replace gate optocouplers to prevent catastrophic future failures.

Microscopic Solder & SMT Reflow

Using ISO-certified temperature-controlled desoldering stations, our IPC-trained technicians replace damaged components. We execute precision micro-soldering under stereo-zoom microscopes for multi-layer PCBs.

Controlled Bench & Load testing

After repair, units are powered on via variable-voltage current-limiting power supplies. We run full closed-loop tests under real load conditions—testing communication links, analog/digital feedback loops, and thermal efficiency.

Final QC Certification & Protective Coating

The repaired PCB is cleaned in an ultrasonic chemical bath to remove flux residues. We apply a high-grade conformal coating to protect against moisture, dust, and corrosive industrial oils before releasing the unit with our warranty.

ISO 9001:2015 Certified

Why Choose Usha Engineering?

26+ Years of B2B Expertise

Established in 2000, we possess over a quarter-century of hands-on industrial electronic repair experience. We are an ISO 9001:2015 Quality Management System certified company.

Up to 70% Cost Savings

Repairing high-end industrial controllers and drives with Usha Engineering is significantly more cost-effective than purchasing expensive new OEM replacement units, which also require configuration.

Advanced Component-Level Lab

Our Panchkula HQ facility features state-of-the-art diagnostic equipment including logical analyzers, digital oscilloscopes, curve tracers, thermal imagers, and dedicated load test benches.

Pan-India Logistics & Quick Turnaround

We accept units shipped via secure courier from anywhere in India, offering express 48-hour turnarounds for critical breakdowns to minimize factory downtime.

Industries We Serve

Steel & Metallurgy

VFDs and PLCs controlling blast furnace loaders, rolling mills, heavy crane lifts, and cooling fans.

Textile & Spinning Mills

High-speed servo drives, HMI panels, and control cards on spinning frames, carding machines, and weaving looms.

Paper & Packaging

Multi-drive tension control systems, synchronous motors, and PLC controllers on web presses and slitting lines.

Pharmaceutical & Chemical

HMIs, PCBs, and control modules in pill press machines, packaging lanes, centrifuge drives, and mixing vessels.

CNC & Automotive Machining

Precision spindle drives, servo controllers, and logic units in 3-axis and 5-axis CNC machining centers.

Warranty Protection

3-Month Service Warranty

We stand behind our work. All board-level repairs performed by Usha Engineering Services are covered by a comprehensive 6-month warranty on replaced components and workmanship. We use only original, high-grade semiconductor parts sourced from certified global distributors.

Need Help Immediately?

Submit a diagnostics ticket or speak directly with an engineer to get a free estimate and arrange unit pickup.

Frequently Asked Questions

Clear answers regarding repair procedures, pricing, and warranties

Why does my SMPS make a high-pitched squealing sound?

This is usually caused by failing filter capacitors, which forces the switching controller to operate at a lower, audible frequency, or due to loose transformer windings vibrating.

Can you repair 3-phase industrial power supplies?

Yes, we repair both single-phase and heavy-duty three-phase industrial power supplies, including high-current DC rectifiers.

Is it worth repairing cheap SMPS units?

For standard low-cost rail SMPS, replacement is often cheaper. However, for specialized, high-current, multi-rail, or DIN-rail PSUs (like Siemens Sitop or Phoenix Contact), repair offers significant savings.

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