Technical Support Document 043 - 8/95

REPLACING THE STARLITE 55 COLORHEAD MOTHERBOARD

The Starlite 55 Colorhead features a modular design which makes it easily serviceable in most cases. The replacement of the colorhead's main computer circuit board, generally called the "motherboard," is no exception. The process requires no soldering, merely a few ordinary hand tools, as listed here:

• Small Phillips Screwdriver (#1 Tip)
• 1/4" Hexagonal Nut Driver
• 3/16" Hexagonal Nut Driver
• Small Flat-Blade Screwdriver (1/8" Blade), 10" length recommended.

The new Starlite 55 Motherboard should be packaged in a silver static-protective bag. Do not remove the new board from this bag until ready to actually mount it into the Starlite enclosure. The procedure for replacing the Starlite 55 motherboard is as follows:

1. Unplug the main AC Power Cord from the receptacle in the rear of the colorhead. This is an important safety precaution since the Motherboard receives direct AC power from the wall socket.
   

2. Open the door to gain access to the interior of the Starlite. Remove the Mixing Box and the Filter/Lamps Transport Assembly. The Motherboard is now in full view.
   
   

3. Unplug the Color Sensor cable from the Motherboard. This is the flat gray cable connected at the lower left corner of the Motherboard.
   
4. Disconnect all other connections to the Motherboard. These connections are listed below:
   

>Mains AC Power: Next to the filter/lamps transport connector, there is a green screw terminal strip with 4 screws. Loosen all four screws to free the two spade connectors inserted into the strip. On some units, two larger brass nuts are used to hold down the connections. Use a pair of pliers to loosen these brass nuts.

>Lamp Power: To the right of the Motherboard is the solid-state relay which controls the lamps. The top two screw terminals are the AC power lines the Starlite's lamps. Loosen the screws to release the spade terminals connected there.

>Lamp Control Lines: The bottom two screws on the solid-state relay are the low-voltage control signals that control the lamps. Undo these connections the same way as the Lamp Power connections. Note that each of these two screw terminals are labeled with a "+" and "-" sign. The Red and Blue wires on the new Motherboard will need to be reconnected in the same orientation.

5. Loosen and remove the two small 3/16" nuts that secure the Motherboard at the filter/lamps transport connector. Save these nuts and the washers for re-installation.
   
6. Loosen and remove the two larger 1/4" nuts that secure the right edge of the Motherboard. Save these nuts for re-installation.
   
7. Loosen and remove the six (6) screws that hold down the rest of the board. The Motherboard should now be free. There may be black felt around the Keypad and Density Probe connectors at the lower left corner of the Motherboard. Remove this felt and discard.
   
8. Lift the Board from the enclosure, raising the right edge from the screw posts first, then working the board out of the enclosure.
   
9. Remove the new Starlite 55 Motherboard from its protective bag. Position the Board into the enclosure, first placing the left edge behind the color sensor, then seating the right edge of the board onto the two screw studs. Be careful that there are no wires under the board when it is in its final location.
   
10. Loosely install the screws and nuts that hold the Board in place. Be sure to install the two washers under the small nuts at the filter/lamps transport connector.
    
11. Tighten the five screws around the left-hand area of the board, then tighten the nuts at the right edge of the board. After all of these are tightened, tighten the two small screws at the filter/lamps transport connector.
    

Once all the nuts and screws are tight, re-connect all of the electrical connections to the Motherboard. These are listed again here for convenience:

>Color Sensor Cable: This is the flat, gray ribbon cable that connects at the lower, left corner of the Motherboard. Be sure that the connection is made such that the red striped wire is nearest the white "1" printed on the circuit board.

>Lamp AC Power Connections: The two large screws at the top edge of the solid-state relay receive the two thick gray wires. Make sure that the screws are very tight, since a loose connection will cause unreliable operation of the colorhead.

>Lamp Control Connections: The two small screws at the bottom edge of the solid-state relay are for the thin red and blue wires of the Lamp control signal. The red wire goes to the terminal on the relay marked with a plus "+" sign. The blue wire goes onto the minus "-" terminal.

>Mains AC Power: The thick black and white wires carry the AC power from the mains wall socket. These wires are connected to the screw terminal strip on the Motherboard. The white wire is connected to the terminals labeled "NEUTRAL" and the black one goes to the "LIVE" terminals. Tighten these screws securely, since a loose connection will cause unpredictable operation of the Starlite. Double check that these two wires are in their proper places, since a reversed connection may cause improper operation of the colorhead.

If the old motherboard had the larger brass terminals, the AC power wires will be terminated with ring terminals that will not fit into the green screw strip. If this is the case, use a pair of wire cutters to clip the top of each ring, then bend the two halves straight out to form a "spade" terminal.

After all electrical connections have been made, double check them to make sure there are no errors, shorts, loose connections, etc.

When sure that all connections are solid and correct, re-install the filter/lamps transport into the colorhead enclosure. Pay careful attention to how the connector on the transport mates with the connector on the Motherboard. If the two are not in good alignment, arcing may result when the colorhead power is turned on, resulting in damage to this connector. If there is misalignment, loosen (but do not remove) all mounting hardware for the motherboard, fully insert the transport assembly into its connector, then re-tighten the screws to hold the board in this position.

1. Install the light mixing chamber. With the mixing chamber and filter/lamps transport in place, close the door to the Starlite.
   
2. Re-connect the mains AC power cord to the rear of the colorhead and turn the power on.
   
3. Verify that the colorhead is working properly. Since this Motherboard is new to this particular Starlite chassis, it will need to calibrated for proper color output. To calibrate the internal color sensor, access the "STARLITE DIAGNOSTICS" menu. Under this menu select the "AUTO-CALIBRATE COLOR SENSOR." This routine will take about 15 seconds for completion.
   

After the sensor calibration is complete, the colorhead will be ready for normal operation and setup. Since the new Motherboard comes with new memory, all standard balance, emulsion, and lens color information will need to be re-programmed.

PLEASE RETURN THE OLD STARLITE 55 MOTHERBOARD TO ZBE WHEN YOU HAVE SUCCESSFULLY INSTALLED THE NEW ONE.

If there are any questions or problems concerning this procedure, please contact ZBE, Inc. at the phone and address information below.