Raymarine SmartPilot S1

The SmartPilot S1 & S1G Course Computer is a core component of Raymarine autopilot systems, designed to process sensor information and steer a boat using a drive unit. This service manual provides detailed procedures for its maintenance, functional testing, and software upgrades.

Function Description

The Course Computer acts as the central processing unit for the autopilot system. It receives data from various sensors, including the fluxgate compass, rate gyro, and rudder reference, to calculate and execute steering commands for the drive unit. The assembly consists of a plastic case housing a printed circuit board (PCB) which contains a microprocessor, electronic circuitry for drive unit control, a power amplifier for the drive motor, and a connector block for all inputs and outputs.

Important Technical Specifications

The Course Computer operates on a 12V DC power supply. It includes two fuses: a 15A fuse for power input and a 2A fuse for SeaTalk communications. The PCB features specific voltage test points for diagnostic purposes: +5V-DIG (4.9V-5.1V), HD-PWR (11.95V-12.05V), and PWR-OV (0V).

The device supports both Murata and Kionix rate gyro modules. For Murata gyros, the R18 resistor value is 100k (0603), while for Kionix gyros (introduced from August 2005 with Revision E PCBs), the R18 resistor value is 113k (0603). For S2G/S3G models, the corresponding resistors are R145 & R147, with values of 10k (0805) for Murata and 11.3k (0805) for Kionix.

A critical component is the C43 Polarised Capacitor (2.2uF 6.3V), which, if incorrectly placed, can cause a fluxgate compass circuit fault leading to compass heading drift, jumps, or inaccuracies.

Usage Features

The SmartPilot S1 & S1G Course Computer integrates with various Raymarine components:

Control Head: Typically an ST6001/2, used for displaying compass heading, rudder angle, and other autopilot data.
Fluxgate Compass: Provides heading information.
Rudder Reference: Supplies rudder position data.
C/E Series Unit: Can be connected via NMEA 1 for waypoint information (XTE, DTW, BTW) and heading transmission.
Drive Unit: A Type 1 pump is mentioned as a typical drive unit.

The system supports SeaTalk communications for seamless integration with other Raymarine devices. Software upgrades can be performed via the NMEA port using a PC running Windows 9x or NT 4.0 and a custom serial download cable.

Maintenance Features

The manual outlines several maintenance and diagnostic procedures:

Initial Inspection Checks:

Remove the connector cover and slide out the PCB.
Verify that the 15A (F1) and 2A (F2) fuses are correctly rated and not blown.
Visually inspect the PCB for component damage or blackening, especially FETs and main power components.
Check the polarity of capacitor C43 (refer to Tech Update TU228).
Verify the resistance value of R18 matches the fitted gyro type (refer to Tech Update TU232).

Functional Tests:

Power Checks: Measure voltages at +5V-DIG, HD-PWR, and PWR-OV test points.
System Checks: Confirm compass heading and rudder angle bar display on the control head, indicating SeaTalk communication functionality. Note that from October 2005, Revision E PCBs with Verado software do not require an external rudder reference device, and the rudder reference bar will not be displayed in standby mode.
Rate Gyro Test: Measure voltage at gyro terminals (nominal 2.5V ± 0.1V) and observe voltage changes when rotating the Course Computer. Replace the gyro if signal levels are unstable or out of tolerance.
Compass Test: Rotate the compass and Course Computer (if gyro fitted) through 90° and 360° to check for smooth heading changes on the control head display.
Rudder Reference Test: Verify rudder offset is zero, and the rudder bar on the display accurately reflects the physical movement of the rudder reference.
Clutch Test (Auto/Standby): Measure voltage at clutch terminals (12V nominal in AUTO, 0V in STANDBY).
H-Bridge Test: Activate the motor with +10 and -10 commands to check spinning in both directions and measure HD-PWR while running.
NMEA Test (Receive/Transmit): Verify waypoint data reception from a C/E Series unit and heading transmission to it.
EEPROM Test: Change a calibration setting (e.g., Drive Type), save, remove/reinstate power, and verify the setting is retained.

Disassembly and Reassembly:

Requires a 3mm Allen key and a cross-head screwdriver.
ESD Precautions: Emphasizes the use of an anti-static station and anti-static straps due to electrostatic sensitive components.
Steps include removing the connector cover, PCB retaining screw, sliding out the PCB, unplugging the rate gyro connector, and removing gyro retaining screws.

Software Upgrade:

Requires a PC with an RS232 port and a custom serial download cable.
Use the SWDL 4 Windows.exe program and specific .INI files (CC115K1.INI or CC115K2.INI).
Critical Warning: Do NOT remove power during file download, as this will render the unit inoperable.

Technical Updates:

TU228 (Fluxgate Compass Circuit Fault): Addresses the issue of incorrectly placed C43 capacitors. The fix involves unsoldering and re-soldering the capacitor in reverse.
TU232 (Introduction of new "Kionix" Rate Gyro module): Details the transition from Murata to Kionix gyros due to obsolescence. It specifies resistor value changes (R18 for S1G, R145 & R147 for S2G/S3G) required for compatibility when replacing gyros or PCBs. Service spares are supplied with appropriate resistors, and checking resistor values against the gyro type is strongly recommended.

The unit contains no serviceable parts at a component level beyond the specified fixes; if a unit fails other diagnostic checks, the PCB or rate gyro should be replaced as necessary.