Case Study

Gyro Repair

Vessel name: AISHA SARWAR

IMO: 9200433

 

Manufacturer: TOKIMEC INC. JAPAN

Gyro Compass

Model: TG-6000

Service Report

Our team arrived on board at 1am on 23.04.2016.

FYI; 23 April is the National Sovereignty and Children's Day in Turkey.

Immediately asked for ex-service report to understand possible cause of error.

Surprisingly there was no report was found by crew at all. Only on the unit cover there was a sticker showing year 2011.

From it is poor condition, we believe it was the first service done to the unit after installation.

From initial inspection the Unit was giving alarm for E3 (inverter) and EA (communication between CPU-SCU)

Step Motor installation fittings were still carrying factory paint. This sign of condition was showing us that up to moment of our service the Unit was not serviced and greased before. Step Motor disassembled, cleaned and greased by our team.  Unit started to work in much smooth mode. All this was supervised and observed by electrician on board.

Sleep rings were in very poor condition; again we believe it was never cleaned before since it should be cleaned at every service. Anyway our team did necessary cleaning of the rings. Again Crew and Captain also saw all this steps.

All bearings and teeth wheels were cleaned and greased by our team as well.

As result of detailed inspection found that; Sensitive Element, MCU PCB, PMCU PCB, Display control panel, STMD PCB,  out of order. Horizontal PCB, Inverter PCB giving an error.

Sensitive element has a designed life time around 5-6 years. During inspection measurement result was extremely high.

Inside gyro MCU-PMCU-Display control panel is are working all together. During inspection test all three components were giving EA communication error. It is mandatory to change all together since software inside is supporting each other.

As for STMD PCB is Step motor’s driving card. It was not sending signal to Motor.

Inverter unit; without connecting to sensitive element, it was giving normal parameters. However after connection to system this value decreased. We connected our sensitive element and started testing. After 40min also our sensitive element failed. It showed us that inverter unit had a problem as well. Therefore INVERTER PCB has been changed. After that our team had to go back to workshop and get another sensitive element. (using extra motor boat on our account)

 

Horizontal PCB; after installation sensitive element during test we saw that rpm was not reaching 9000. During that we also understood that it was not sending signal from time to time. After checking all electrical connections, (the common decision taken) decision given to change this card.

All parts tested one by one with supervision of the crew. Following part changed with reconditioned units on exchange base with Captains approval; Inverter, PMCU PCB, MCU PCB, Sensitive Element, Horizontal PCB, Inverter, STMD PCB.

Sensitive Element unit tested 110V-400Hz—OK

Inverter unit tested 23.96VDC—OK

Waited for 2 hours to settle.

Job completed at 12pm (Please see attached service report 1) and our team called for motor boat.

However due to problem of Autopilot captain did not allow our team to go ashore and asked our assistance.

With goodwill our team checked the problem but, due to lack of spare parts, they could not touch the unit. (Please see attached service report 2)

After getting approval signature from