Soft Starter Repair
SCR-based soft starter repair for all brands — thyristor replacement, firing circuit repair, control card diagnosis, bypass contactor service, and full motor start testing.
India's trusted soft starter repair specialists. Our SCR-level diagnostic capability, firing circuit expertise, and dedicated motor start test bench allow us to pinpoint thyristor failures, gate drive faults, and control card issues with scientific accuracy — saving you the cost of a new unit.
Soft starters protect motors by gradually ramping up voltage during startup, reducing mechanical stress, inrush current, and voltage dips on the supply network. When a soft starter fails — whether from a blown SCR, faulty firing circuit, or crashed control card — the motor cannot start, and production halts immediately. Synchronics repairs soft starters at the SCR/thyristor level, diagnosing and replacing faulty gate drive circuits, power thyristors, control boards, and bypass contactors with precision testing at every stage.
Diagnosis Guide
Common Soft Starter Problems We Fix
Experiencing any of these symptoms? Our engineers have diagnosed and repaired thousands of these faults.
SCR/Thyristor Failure
Motor does not start, starter trips on overcurrent at start, one or two phases missing at output
Supply voltage transients, motor winding short, excessive starting cycles, SCR ageing
Control Card Crash
No display on starter, blank screen, starter does not respond to start command, error LED blinking
Power surge, firmware corruption, electrolytic capacitor failure, ESD damage
Firing Circuit Fault
SCRs not turning on properly, unbalanced motor current, erratic starting behaviour, motor humming without rotation
Pulse transformer failure, optocoupler degradation, gate resistor open, firing board component failure
Bypass Contactor Stuck
Starter does not transition to bypass after ramp, motor runs continuously through SCRs causing overheating, contactor chattering
Contactor coil failure, contact welding, auxiliary relay fault, control signal loss
False Overload Trips
Starter trips on overload even with no load, nuisance tripping during normal operation, current reading incorrect
Current transformer drift, CT wiring fault, protection parameter misconfiguration, CT hardware failure
Communication Module Failure
No data on fieldbus, soft starter not visible on network, intermittent communication drops, parameter read errors
Communication module IC failure, connector pin damage, bus termination issue, protocol mismatch
How It Works
Our Soft Starter Repair Process
A systematic, schematic-driven repair process — from receipt to dispatch.
Receive & Visual Inspect
Soft starter is logged into our ERP system with full photographic documentation. Visual inspection for burnt SCRs, swollen capacitors, damaged connectors, and contactor condition.
SCR/Thyristor Test
Each SCR module is individually tested for forward/reverse blocking, gate trigger threshold, holding current, and thermal characteristics using our dedicated thyristor test rig.
Firing Circuit Diagnosis
Firing angle control circuit tested with oscilloscope — gate pulse timing, pulse transformer output, optocoupler transfer ratio, and synchronisation with AC supply verified.
Control Board Repair
Failed components on control and firing boards are replaced — ICs, capacitors, MOSFETs, optocouplers, regulators — using genuine or equivalent-spec parts from inventory.
Motor Parameter Setup
Start ramp time, stop ramp time, initial voltage, current limit, motor FLC, and protection parameters configured per customer motor and application requirements.
Motor Start Test & Dispatch
Repaired soft starter tested with actual motor on our test bench — full start/stop cycle, bypass transition, current monitoring, and thermal verification. Warranty certificate issued.
Thorough Inspection
What We Inspect in Every Soft Starter
Every unit goes through a comprehensive inspection checklist before and after repair.
SCR/Thyristor Modules
Firing / Gate Circuit
Control Board
Bypass Contactor
Protection Circuits
Cooling System
The Synchronics Advantage
Why Choose Us for Soft Starter Repair
SCR-Level Diagnostic Expertise
Our engineers test each thyristor individually for blocking voltage, gate threshold, and thermal characteristics — identifying marginal SCRs that pass basic checks but fail under load.
Motor Start Profile Tuning
We do not just repair the hardware — we optimise start ramp, voltage kick, current limit, and deceleration parameters for your specific motor and load, ensuring smooth and reliable starts.
Full Motor Start Testing
Every repaired soft starter is tested with an actual induction motor on our test bench — verifying ramp-up, bypass transition, current profile, and thermal behaviour under real starting conditions.
Troubleshooting
Common Soft Starter Fault Codes We Fix
Seeing one of these error codes? We diagnose and repair the root cause.
SCR thyristor short circuit or failure detected
SCR module failure, gate driver fault, supply transient damage
Motor current exceeded overload threshold
Motor overloaded, incorrect FLC setting, current transformer drift, mechanical jam
One or more input/output phases missing
Supply fuse blown, SCR open circuit on one phase, loose power terminal, cable fault
Soft starter internal temperature exceeded limit
Cooling fan failure, heatsink blocked, excessive starting duty, high ambient temperature
Motor failed to reach speed within time limit
Mechanical jam, initial voltage too low, ramp time too short, motor fault
Communication with fieldbus or PLC lost
Communication module failure, bus wiring fault, incorrect baud rate or address, termination resistor missing
Fault codes and nomenclature vary by manufacturer (ABB PSTX, Schneider Altistart, Siemens 3RW, etc.). Contact us with your specific soft starter model and fault display for expert diagnosis.
Industries Served
Where Soft Starters Are Used
Water Pumping Stations
Submersible pump starters, booster pump systems, raw water intake motors
HVAC & Compressors
Chiller compressor starters, AHU fan motors, cooling tower drives
Conveyor Systems
Belt conveyor motor starters, feeder drives, bucket elevator motors
Mining & Crushers
Jaw crusher motors, ball mill starters, heavy-duty conveyor drives
Cement Plants
Kiln auxiliary motors, raw mill starters, cement mill fan motors
Chemical Processing
Agitator motor starters, reactor feed pumps, centrifuge drive motors
Trusted Brands
Brands We Service
Component-level repair for all major manufacturers
FAQ
Frequently Asked Questions
Repairing at the component level — replacing only the failed SCRs, firing circuits, or control board ICs — costs 40-60% less than a new soft starter and can be completed within 48 hours. A new unit may involve 4-8 weeks of import lead time for certain brands. Our 6-month warranty on repairs ensures you get reliable performance at a fraction of the cost.
Yes. SCR/thyristor module replacement is one of our most common soft starter repairs. We replace the failed SCR with a matched-spec module, renew the thermal interface, and always investigate the root cause — whether supply transients, motor fault, or excessive starting duty — to prevent recurrence.
Yes. Every repaired soft starter is connected to an induction motor on our test bench and put through a complete start-stop cycle. We verify the ramp-up current profile, bypass contactor transition, and thermal performance under real motor starting conditions before dispatch.
Yes. If only the Profibus, DeviceNet, Modbus, or Ethernet communication module is faulty, we can repair or replace it independently without disturbing the main power and control sections. This is particularly cost-effective for soft starters that are otherwise fully functional.
Soft Starter Repair Services Across India
Synchronics provides expert soft starter repair services for industries across India — Vadodara, Ahmedabad, Mumbai, Pune, Chennai, Bangalore, Delhi, Kolkata, and all major industrial cities. Our pan-India logistics network ensures your soft starter reaches our facility safely and is returned promptly after repair.
Whether you have a compact 15A soft starter from an HVAC compressor or an 800A heavy-duty unit from a cement plant crusher, our team of 180+ engineers has the SCR-level expertise and motor test infrastructure to diagnose and repair it right the first time. We service all brands including ABB PSTX, Schneider Altistart, Siemens 3RW, Allen Bradley SMC, Danfoss MCD, Eaton, and WEG — restoring your motor starting capability without new-unit cost and lead time.
Get Your Equipment
Back in Action — Fast
Send us your faulty industrial electronics. Our engineers will diagnose it and provide a detailed quote within 24 hours — with no obligation to proceed.
Free Evaluation
No obligation
48hr Turnaround
Fastest in India
6-Month Warranty
Every repair
No Fix, No Charge
Zero risk policy
Pan-India Pickup
Doorstep service