Repair Case: SGMPH-15A1A-YR11 Servo Motor

01.07.2025 by Viktor Siebert

Repair Case: SGMPH-15A1A-YR11 Servo Motor – A Costly Mistake Avoided

Inquiry from a Paint Machine Manufacturer.

A manufacturer of painting systems using Yaskawa robots contacted us. The required motor type SGMPH-15A1A-YR11 was no longer available from Yaskawa. The official feedback: “Either replace the robot or figure out a solution yourself.”

Counterfeit Motor Purchased Online

In an attempt to solve the issue, the customer ordered a supposed replacement motor online. It arrived looking new, but was actually a relabelled and rebuilt counterfeit. The encoder (UTSAH-B16DC-E) was falsely programmed to represent a SGMGH-44 type motor.

Drive Damage During Installation

When installed, the motor immediately caused a critical failure of the drive (type SGDH-15AE). Smoke appeared, and the drive was completely destroyed. The Chinese seller provided a video showing the motor running – but not the drive or load conditions.

Internal Damage and Encoder Corrosion

Opening the encoder cover revealed heavy corrosion, poor soldering, and internal rust. The encoder was in very bad condition and had clearly been tampered with.

Costly Consequences

The customer had to purchase a new Yaskawa drive, costing nearly €3,000. What seemed like a quick and cheap fix ended up being an expensive lesson.

Our Repair Solution

The customer sent us the original SGMPH-15A1A-YR11 motor, equipped with encoder UTSAH-B16DC-E and a 90 V holding brake (OGURA MCNB73Y-03).

Our Repair Process

Complete disassembly and visual inspection
Intensive cleaning and surface refinishing
Bearing replacement
Installation of a brand-new encoder, custom-programmed for this motor
Brake check (no replacement required)

Test Procedure

Test bench: SGDH platform
Jog test, reference movement
Run-up to rated and max speed (1500 RPM)
Several hours of load testing
Monitoring of temperature, current, encoder signals

The motor passed all tests and was returned. It has now been running for over a week without any issues in the customer’s production line.

Further Motors Sent In

The same customer has already sent us more SGMPH motors from another line for repair. We continue to provide reliable, technically precise service where OEMs and the internet fall short.