Northstar 972DH Install Guide Dual Head Support for 972 Thank you for purchasing a second Control Head for your Northstar 972 Integrated Chart Plotter. This accessory kit allows you to install a Control Head for your 972 at a second steering station that mimics the behaviour of the first head. This document describes the components of the dual head support install kit (972DH-IK) and how to install and troubleshoot them. For warranty information and install information related to the Control Head, please refer to the install manual included with the control head. What's in the Box This install kit includes a Y-Cable for the control signals, a six foot DVI cable and a DVI mini hub. Qty 1 1 1 Part name DVI Mini Hub w/Integrated Mtg Bracket & 6 Ft DVI Cable 972 Control Head Y-Cable Northstar 972DH Install Guide Part number MINIDVI WA621 GM972DH Critical Do's and Don'ts · Never put an extension between the Black Box and the Y-Cable. · Alway use good practice in cable routing, securing and service loops. · Be sure to mount the DVI Mini Hub in a dry location. It is not waterproof. · Mount the DVI Mini Hub close to the black box for ease of service. · Be sure to use service / drip loops -- they provide a path for any water to drip away from the equipment as well as easy access for service of the equipment. · Always tighten jackscrews on DVI connectors. Otherwise, they will not function properly. Basic Installation Find a suitable location for the DVI Mini Hub. A good location will be: · within six feet of the Black Box · dry -- the DVI Mini Hub is NOT waterproof · easily accessible Secure the DVI Mini Hub using the integrated mounting bracket. Electrical Connections Connect the included 6-foot DVI cable between the Black Box and the DVI Mini Hub. Then connect the two Control Head DVI cables to the other side of the Mini Hub. To assure a secure connection, be sure to tighten the jackscrews on all DVI connectors. Connect the Y-Cable for the control signals to the Black Box. The Y-Cable must be connected directly to the Black Box for your system to work properly. Then connect the two Control Head cables to the Y-Cable. Verify proper operation of the system by turning on both heads and observing normal operation. GM972DH Northstar 972 Dual Head Install Guide Revision B Wiring Diagram 12 or 24V DC Power 972 Control Head - Upper Helm 972 Black Box Note 2 Note 3 Pwr Ctl WA621 Y-Cable Mount in a dry location 6 ft. DVI Cable Keep connectors dry DVI Mini Hub DVI Cables WC276-9 or WC276-15 12 or 24V DC Power Note 1 972 Control Head - Lower Helm Control Cables WA612-9 or WA612-15 Pwr Ctl Note 1: Connect WA621 Y-Cable directly to Black Box. Do not extend the cable. Keep connectors dry. Note 2: Use only DVI cable included in 972DH-IK to connect DVI Mini Hub to Black Box. Note 3: Mount DVI Mini Hub in dry location; it is not waterproof. Troubleshooting Control heads turn themselves on or off If you experience problems with heads turning themselves on or off, it's most likely due to ground lift within your system. This means that ground at the Black Box is different from the ground at a Control Head. This is caused by a voltage drop over the cables connecting the equipment to the voltage source (battery). Verify this by measuring the voltage between the two grounds with a voltmeter. Best practice suggests this voltage ought not be over 100mV (0.1V) Isolate the DVI Mini Hub by connecting the suspect Control Head directly to the Black Box. If the display is still not working, try another Control Head or DVI monitor. Then try another DVI cable. This systematic approach isolates each component in the display chain. As above with the display function, try connecting the suspect control cable directly to the Black Box -- without the Y-Cable in place. An alternate control cable and Y-Cable may be substituted as well to help isolate the problem. Display not functioning Keyboard not functioning GM972DH Northstar 972 Dual Head Install Guide Revision B ...