JVC 250 service manual Miscellaneous Items

Chapter 2---System Description

provides an interconnection interface for all the electronic components in the projector.

CRT/Yoke Assemblies

The CRT/Yoke Assemblies bridge between the Optical and the Electronic sections. The CRTs could be included in the Optical section because they produces the image light transmitted to the ILA® s, but they are included in the Electronic section because they are the end user for the image signals from the VICs, Video Processor PCB, and Video Amplifier PCB. The CRTs also use the Anode, Focus, G1, and G2 voltages from the High Voltage Power Supply. The Yoke Assemblies contains the deflection and convergence coils. The deflection coils are the end-user for the horizontal and vertical deflection waveforms from the Horizontal Vertical Deflection PCB. The convergence coils use the convergence data from the Convergence Deflection PCB.

2.5Miscellaneous Items

The Miscellaneous Items section consists of components that indirectly support the main function of the projector.

Projector Covers

All Series 200 projectors including the Model 250 have a front and rear cover. Both covers can be tilted up and/or removed to service the projector. The covers should not be opened while the projector is operating without proper safety protection (review the Safety Chapter).

IR Detectors

The Model 250 can be controlled by a handheld IR Remote Control. The IR (Infrared) Detectors receive infrared pulses from these remote controls and use them to control various functions of the projector. One IR Detector is mounted on the front of the projector, the other is mounted on the System Controller PCB at the rear of the projector. IR Detectors can receive commands from the remote control from a range of about 45-ft. line of sight.

Cooling Fans

The Model 250 has eleven cooling fans of various sizes plus a large blower for the Arc Lamp. The cooling fans maintain thermal stability for the projector. The Arc Lamp especially depends on the cooling fans. If the fans are not operating while the Arc Lamp is on, the Lamp will implode from overheating. Many of the Printed Circuit Boards generate a lot of heat and require airflow from the cooling fans. The fans provide cooling to the PCBs and CRTs to maintain for stable operation.

Air Filters

The Model 250 has three air filters (see Figure 2-2). The Air Filters filter the incoming air to minimize the amount of dust and air-borne particles inside the

Model 250 Service Manual 2-7