JVC 250 service manual System Controller PCB Remove and Replace

Chapter 5---Electronics

Controller PCB also enables the selected VICs through the IIC bus based on the VIC selected on the Channel Menu.

The System Controller PCB generates the on-screen menus and test pattern overlays and sends them to the Video Processor PCB. It sends the X and Y Convergence correction data to the Convergence Deflection PCB. It sends Threshold and Sensitivity shading data to the Video Processor PCB for the all three colors. The System Controller PCB stores all the configuration data such as Geometry, Convergence, Shading, ILA® Bias and Sensitivity, and G2 settings etc. in flash memory and allows that data to be exported to, or imported from a floppy disk.

The System Controller PCB displays system status through a single three-color LED visible on the back panel. A green light indicates normal operation, the yellow indicates standby operation, and red indicates a fault or error condition.

The System Controller PCB has an External Service Mode Switch that enables the operator to switch from the normal operating mode to a diagnostic mode. If there is a new release of system software, it can be uploaded into the projector by switching into the diagnostic mode. The procedure for this is in the Software and Protocol section (see Chapter 8, Software and Protocol).

System Controller PCB - Remove and Replace

Tools Needed

#1 Pozi-drive Phillips-head screwdriver

#0 Pozi-drive Phillips-head screwdriver

Parts Needed

System Controller PCB - p/n 104678

To remove the System Controller PCB:

1.Power OFF the projector by IR Remote or PC, and allow the cooling fans to run until they shut off automatically.

2.Turn the AC Circuit Breaker to the OFF position and unplug the AC Power Cord.

3.Disconnect all the external source video cables and control cables.

4.Remove the rear cover.

5.Remove the Back Panel. Remove the nine Pozi-drive Phillips-head retaining screws using the #1 Pozi-drive Phillips screwdriver.

6.Remove the Connector Bracket by removing the single Pozi-drive Flathead Phillips-head screw using the #0 Pozi-drive Phillips screwdriver.

7.Pull the black Card Extractor handles back to disconnect the System Controller PCB connector and pull the PCB out of the Electronics Module.

8.Reverse the procedure to install the System Controller PCB.

5-10 Model 250 Service Manual