Vanguard Instruments Repair
The ATRT, WRM, LTCA, ATO, DMOM, AUTO-OHM, CT-series, DigiTMR, EZCT, IRM and VBT instruments are still working in substations all over India — long after the factory stopped supporting them. We repair them at component level, discontinued or not.
88
Vanguard models listed
55
Discontinued models covered
Free
Diagnosis & fixed quote
Pan India
Ship from anywhere
Vanguard was its own company — and its instruments outlived the brand
Vanguard Instruments Company of Ontario, California spent decades building rugged, straightforward substation test equipment: transformer turns ratio testers, winding resistance meters, load tap changer analysers, micro-ohmmeters, circuit breaker timers, CT testers and vacuum bottle testers. They were popular in India for exactly the reasons you would expect — they were simple to operate, they were built like tanks, and they did one job properly.
Vanguard was subsequently acquired by Doble Engineering. The brand still appears on the current Doble catalogue for the models that survived the transition — the TRF and TRM series, the TDR breaker analysers, the AUTO-OHM S4 and the EZCT-2000C. But the older catalogue did not survive it. Search for a CT-6500, a WRM-40, an ATO-600, a DMOM-200, an ATRT-03A, an EZCT-2000A, an IRM-5000 or a VBT-80 on the manufacturer's site today and you will find nothing at all.
Those instruments did not stop working when the web page disappeared. Thousands of them are still in daily service in Indian utility substations, transformer works, testing agencies and EPC contractors' toolkits — and when one of them fails, the owner discovers there is no factory repair route, no spare boards and no support line. That is the gap this page is here to fill.
The good news is that these are honest, repairable instruments. The measurement front end and the mechanics almost always outlive the electronics, and what actually fails is usually mundane: a power supply, a display, a keypad, a thermal printer, a battery pack, a current source stage or a travel transducer. All of that is routine component-level work.
Every Vanguard model, including the discontinued ones
88 models across both the original Vanguard Instruments catalogue and the current Doble-era line. Tick discontinued only to see the 55 models the factory no longer supports.
88 models shown
Transformer Turns Ratio (TTR) Testers
Single-phase and three-phase automatic TTR sets with load tap changer control — from the original ATRT-01 through today's TRF series.
ATRT-01
LegacyOriginal automatic single-phase transformer turns ratio tester.
ATRT-01B
LegacySingle-phase TTR with battery operation for field use.
ATRT-01D
LegacySingle-phase TTR with expanded display and storage.
ATRT-01 S3
Automatic 40 Vac single-phase transformer turns ratio tester.
ATRT-01B S3
Single-phase turns ratio tester with AC or battery operation.
ATRT-03
LegacyOriginal automatic three-phase transformer turns ratio tester.
ATRT-03A
LegacyThree-phase TTR with automatic tap changer sequencing.
ATRT-03A S2
LegacySeries 2 revision of the three-phase ATRT-03A.
ATRT-03B
LegacyThree-phase TTR with extended voltage output.
ATRT-03B S2
LegacySeries 2 revision of the three-phase ATRT-03B.
ATRT-03 S2
Automatic 100 Vac three-phase turns ratio tester with LTC control.
AccuTRANS
LegacyPortable transformer turns ratio measurement instrument.
TRF-100
Automatic 100 Vac three-phase transformer turns ratio test set.
TRF-250
Automatic 250 Vac three-phase turns ratio test set with LTC control.
TRF-250 A
Three-phase 250 Vac turns ratio set, AC or battery powered.
Winding Resistance & LTC Analysers
DC winding resistance meters with load tap changer testing and automatic discharge — the WRM and LTCA families through to today's TRM series.
WRM-10
Legacy10 Adc transformer winding resistance meter.
WRM-10P
Legacy10 Adc winding resistance meter with built-in thermal printer.
WRM-40
Legacy40 Adc transformer winding resistance meter.
LTCA-10
Legacy10 A load tap changer analyser for OLTC contact diagnostics.
LTCA-40
Legacy40 A load tap changer analyser for OLTC contact diagnostics.
Herculito
LegacyCompact portable winding resistance and micro-ohm meter.
TRM-20
Automatic 25 Adc winding resistance test set with LTC test.
TRM-40
Automatic 40 Adc winding resistance test set with LTC test.
TRM-203
Automatic 25 Adc three-phase winding resistance test set.
TRM-403
Automatic 40 Adc three-phase winding resistance test set.
TSB
Test switch box connecting winding resistance and turns ratio meters.
Micro-ohmmeters & Contact Resistance
True DC micro-ohmmeters for breaker contact and busbar joint resistance — the ATO, DMOM, AccuOhm and AUTO-OHM families.
ATO-250
Legacy250 A true DC micro-ohmmeter for contact resistance.
ATO-400
Legacy400 A true DC micro-ohmmeter.
ATO-400P
Legacy400 A micro-ohmmeter with integral printer.
ATO-600
Legacy600 A true DC micro-ohmmeter for high-current joints.
ATO-600P
Legacy600 A micro-ohmmeter with integral printer.
AccuOhm
LegacyPortable digital micro-ohmmeter for field resistance testing.
AccuOhm 200
Legacy200 A portable digital micro-ohmmeter.
DMOM-100
Legacy100 A digital micro-ohmmeter.
DMOM-200
Legacy200 A digital micro-ohmmeter for breaker contact resistance.
AUTO-OHM 100
Legacy100 A automatic true DC micro-ohmmeter.
AUTO-OHM 100 Series 2
LegacySeries 2 revision of the 100 A AUTO-OHM.
AUTO-OHM 200
Legacy200 A automatic true DC micro-ohmmeter.
AUTO-OHM 200 Series 2
LegacySeries 2 revision of the 200 A AUTO-OHM.
AUTO-OHM 10
Compact 10 A true DC micro-ohmmeter with AC or battery power.
AUTO-OHM 200 S4
High-current lightweight true DC contact resistance tester.
Circuit Breaker Analysers & Timers
Digital breaker timing and travel analysers — the long-running CT series, DigiTMR and today's TDR analysers.
CT-3000
LegacyDigital circuit breaker timer for basic timing verification.
CT-3500
LegacyDigital circuit breaker timing analyser.
CT-6500
LegacyMulti-channel circuit breaker timing and travel analyser.
CT-7000
LegacyAdvanced digital circuit breaker analyser.
CT-7500
LegacyCircuit breaker analyser with extended channel count.
CT-8000
LegacyBreaker analyser with integral contact resistance source.
CT-3500 S2
Digital circuit breaker timer for timing verification.
CT-7000 S3
Advanced digital circuit breaker analyser.
CT-8000 S3
Breaker analyser with integral 200 A contact resistance source.
DigiTMR
LegacyOriginal digital circuit breaker timing analyser.
VIC DigiTMR
LegacyVacuum interrupter and contact digital timing analyser.
DigiTMR S2
Digital circuit breaker analyser for timing and motion.
TDR900
Digital circuit breaker analyser — timing, travel and coil current.
TDR9100
Advanced digital circuit breaker analyser with expanded channels.
CBPS-300
LegacyCircuit breaker power supply for coil and motor testing.
CBCT
Programmable DC power supply for breaker control circuit testing.
MCCB-250
250 A moulded case circuit breaker tester.
UPS-2
LegacyVariable AC/DC power supply for breaker test applications.
QuickShot
LegacyPortable breaker timing verification instrument.
Vacuum Bottle & Interrupter Testers
DC hipot testers verifying vacuum interrupter integrity in MV switchgear.
VBT-60
Legacy60 kVdc vacuum bottle tester.
VBT-80
Legacy80 kVdc vacuum bottle tester.
VBT-80P
Legacy80 kVdc vacuum bottle tester with integral printer.
VBT-75 S2
75 kVdc vacuum bottle tester.
VBT-75P S2
75 kVdc vacuum bottle tester with printer and keypad.
CT Testers & Insulation Resistance
Automated current transformer analysers and insulation resistance meters — the EZCT and IRM families.
EZCT
LegacyOriginal automated current transformer test set.
EZCT-10
Legacy10 kV automated current transformer test set.
EZCT-2000
LegacyAutomated 2 kV CT test set for ratio and saturation.
EZCT-2000A
LegacyRevision A of the 2 kV automated CT test set.
EZCT-2000B
LegacyRevision B of the 2 kV automated CT test set.
EZCT-S2
LegacySeries 2 automated current transformer test set.
EZCT-S2A
LegacySeries 2A automated current transformer test set.
EZCT-2000C
Automated 2 kV CT test set with insulation resistance and burden tests.
EZCT-2KA
Automated 2 kV current transformer test set.
IRM-5000
Legacy5 kV insulation resistance meter (megohmmeter).
IRM-5000L
Legacy5 kV insulation resistance meter, extended range.
IRM-5000P
Legacy5 kV insulation resistance meter with integral printer.
IRM-5100
Legacy5 kV insulation resistance meter with data storage.
Relay, Recloser & Ground Jumper Testing
Relay and recloser test equipment plus in-service protective ground jumper testers.
RFD-200
LegacyRecloser and sectionaliser field test set.
TriPhase
LegacyThree-phase relay test system.
PCI-600
Primary current injection system for CT-to-relay loop testing.
JT-200 Ground Jumper Tester
In-service protective ground jumper testing.
Motion Transducers & Accessories
Linear, rotary and string travel transducers that mount to breaker mechanisms — a very common failure point on ageing analysers.
Linear Motion Transducer
Linear travel transducer for breaker contact motion.
Rotary Motion Transducer
Rotary travel transducer for breaker mechanism angle.
String Transducer
String-pull travel transducer for breaker motion measurement.
Type 2 Rotary Digital Transducer
Digital rotary transducer for bracket or adapter mounting.
Type 3 Rotary Digital Transducer
Digital rotary transducer with flex arm and magnet mount.
Digital Linear Transducers
Digital linear travel transducers for breaker analysers.
Vanguard produced variants and OEM-badged versions that never appeared in the public catalogue. If your nameplate does not match anything above, send us a photo of it — we will identify it and tell you whether it is repairable.
Common faults on ageing Vanguard instruments
Displays, Keypads & Thermal Printers
By far the most common Vanguard complaint. Failed LCD panels and backlights, unresponsive membrane keypads, and thermal printers that jam, print faint or stop feeding on WRM, ATRT, ATO, CT-series and EZCT instruments.
Power Supplies & Battery Packs
SMPS failures from unstable substation supply, blown mains input sections, failed charging circuits and swollen or dead internal battery packs on the portable, battery-powered field sets.
Current Source & Output Stages
Dead or weak DC current sources on ATO, DMOM, AUTO-OHM and WRM meters — the unit powers up but cannot reach rated test current, or trips out under load.
Processor Boards & Firmware
Units stuck at boot, corrupt firmware, dead EEPROM, failed real-time clock batteries and lost calibration constants on older ATRT and CT-series analysers.
Travel Transducers & Leads
Broken linear, rotary and string transducers, damaged transducer cabling and worn test lead assemblies on breaker timing analysers — often the actual fault when timing results go erratic.
Measurement Channels
Drifting or dead sense channels, failed ADCs, blown input protection and open current shunts causing readings that are out of tolerance or will not repeat.
Please note: we do not offer courier pickup or drop, and we do not carry out on-site installation or commissioning. Ship the instrument to our Vadodara facility and we return it by courier after repair. Where another repairer has already opened the unit, an inspection charge applies — we tell you the amount before you ship.
Discontinued Vanguard test equipment repair in India
If you are searching for someone to repair a Vanguard instrument, you have probably already discovered that the manufacturer's website no longer lists it. Vanguard Instruments Company was absorbed into Doble Engineering, the old product pages were retired, and an entire generation of substation test equipment quietly became unsupported overnight. The instruments themselves carried on working.
Synchronics Electronics repairs those instruments at component level from our Vadodara facility. We are an independent repair company — not a Doble or Vanguard authorised centre — and our work is specifically aimed at equipment that the OEM has declared end-of-life. Our engineers trace faults on the actual circuit board rather than swapping assemblies, which is the only workable approach when the assembly in question has not been manufactured for well over a decade.
The instruments we see most often are the transformer turns ratio testers (ATRT-01, ATRT-01B, ATRT-01D, ATRT-03, ATRT-03A, ATRT-03B and AccuTRANS), the winding resistance and tap changer analysers (WRM-10, WRM-10P, WRM-40, LTCA-10, LTCA-40 and Herculito), the micro-ohmmeters (ATO-250, ATO-400, ATO-400P, ATO-600, ATO-600P, AccuOhm, DMOM-100, DMOM-200, AUTO-OHM 100 and AUTO-OHM 200), the circuit breaker timing analysers (CT-3000, CT-3500, CT-6500, CT-7000, CT-7500, CT-8000, DigiTMR, VIC DigiTMR, CBPS-300 and QuickShot), the CT test sets (EZCT, EZCT-10, EZCT-2000, EZCT-2000A, EZCT-2000B and EZCT-S2), the insulation resistance meters (IRM-5000, IRM-5000L, IRM-5000P and IRM-5100) and the vacuum bottle testers (VBT-60, VBT-80 and VBT-80P).
Typical faults are unglamorous and very fixable: a failed switch-mode power supply, a dead LCD or backlight, an unresponsive membrane keypad, a thermal printer that will no longer feed, a swollen battery pack, a current source that cannot reach rated output, a broken travel transducer, or a measurement channel that has drifted out of tolerance. Where a specific obsolete component simply cannot be sourced, our PCB reverse engineering team redesigns that section of the board to restore the original behaviour.
Diagnosis is free, the quote is fixed before any work begins, and if we believe an instrument is beyond economic repair we will tell you so rather than bill you for a doomed attempt. We functionally verify the repaired unit against our reference standards and supply a test report — but we are not an accredited calibration laboratory, so if your quality system requires a NABL certificate, arrange accredited calibration after the repair.
For current-catalogue Doble instruments see Doble test equipment repair, for OMICRON see OMICRON test equipment repair, and for the full cross-brand picture start at our electrical test equipment repair hub. If your instrument is a different make entirely, our discontinued equipment repair and PCB reverse engineering services cover the same ground.
Vanguard repair — straight answers
Vanguard Instruments Company was acquired by Doble Engineering, and vanguard-instruments.com now redirects to doble.com. Doble continues the current line — the TRF, TRM, TDR, AUTO-OHM S4 and EZCT-2000C models. What did not carry over is the older catalogue. Instruments like the CT-6500, WRM-40, ATO-600, DMOM-200, ATRT-03A, EZCT-2000A, IRM-5000 and VBT-80 are end-of-life: no factory repair, no spares, no support. Those are precisely the units we take.
All of them, current and discontinued. ATRT-01, ATRT-01B, ATRT-01D, ATRT-03, ATRT-03A, ATRT-03B and AccuTRANS turns ratio testers; WRM-10, WRM-10P, WRM-40, LTCA-10, LTCA-40 and Herculito winding resistance and tap changer analysers; ATO-250, ATO-400, ATO-600, AccuOhm, DMOM-100, DMOM-200 and the AUTO-OHM 100/200 micro-ohmmeters; CT-3000, CT-3500, CT-6500, CT-7000, CT-7500, CT-8000, DigiTMR, VIC DigiTMR, CBPS-300 and QuickShot breaker timers; EZCT, EZCT-10, EZCT-2000/A/B and EZCT-S2 CT testers; IRM-5000, IRM-5000L, IRM-5000P and IRM-5100 megohmmeters; VBT-60, VBT-80 and VBT-80P vacuum bottle testers; and RFD-200 and TriPhase relay/recloser equipment.
Not usually. "Obsolete" from an OEM means they no longer stock the assembly or run the production test rig — it does not mean the fault is unfixable. We work at component level on the actual circuit, so a failed regulator, a dead driver transistor, a cracked solder joint or a blown shunt is a routine repair regardless of the instrument's age. Where a specific IC is genuinely unobtainable anywhere, our PCB reverse engineering team can redesign that section of the board to restore the original function.
Often, yes — these instruments were built to last and the mechanics and measurement front end usually outlive the electronics that fail. Replacing a WRM-40 or a CT-7000 with a current-generation equivalent is a substantial capital purchase with a long procurement cycle. A power supply, display or printer repair is a small fraction of that. We give you a free diagnosis and a fixed quote first, and if we judge a unit beyond economic repair we will tell you that plainly rather than take the job.
We functionally verify the instrument across its measurement ranges against our reference standards and supply a test report with the repair. We are a repair house, not an accredited calibration laboratory — if you need a NABL-accredited certificate for audit or statutory purposes, have the unit calibrated at an accredited lab after our repair.
No. We are an independent repair company with no affiliation to, authorisation from, or endorsement by Doble Engineering Company or Vanguard Instruments Company. If your instrument is still covered by OEM warranty or contract, use that first — third-party repair will void it. We exist for the out-of-warranty and end-of-life units.
Disclaimer
Vanguard Instruments, ATRT, AccuTRANS, AccuOhm, AUTO-OHM, DigiTMR, Herculito, EZCT and all associated model designations are trademarks of Vanguard Instruments Company / Doble Engineering Company. Synchronics Electronics Pvt. Ltd. is an independent third-party repair provider and is not affiliated with, authorised by, sponsored by or endorsed by Doble Engineering Company or Vanguard Instruments Company. Product names and model numbers are used solely to identify the equipment on which repair services are offered, and no trademark ownership is claimed or implied. Synchronics is not an accredited calibration laboratory; repaired instruments are functionally verified against our reference standards and supplied with a test report, not an accredited calibration certificate.
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