Removal of SSB Panel
1. Remove panel support clip (AC04).
2. Tilt top of SSB to the right and then up.
Complete Optical Assembly or Individual Light Box Assemblies
1. Perform Lower Back Cover removal procedure.
2. Perform Speaker Baffle removal procedure.
3. Perform Lens Frame removal procedure.
4. Perform Upper Back Cover removal procedure.
5. Disconnect the CRT Panels, 2nd anode leads (at HVT), and yoke connectors from all CRT assemblies.
6. Remove 4 screws located at front of Optical assembly and lift assembly up and out.
7. To remove individual CRT assemblies, loosen 4 screws located in the assembly you wish to remove
and lift assembly up and out.
Service Position
(Note: Side Jack and Front Control Panels may have to be removed to allow cable slack.)
1. Perform Back Cover removal procedure.
2. Remove 7 screws (I).
3. Pull Chassis Frame back and up.
4. Tilt Chassis Frame upward on bottom of PTV.
Picture Tube Replacement
Refer to CRT Assembly Exploded View
Replacement of the cathode ray tube (CRT) and/or optical system components of a Projection TV (PTV) can be
easily accomplished by following general guidelines. Use care when working around the CRT and optical
systems of the PTV. The PTV light path encompasses a number of precision optical components. These include
lenses, mirrors, the lenticular screen, and Fresnel lens. The PTV incorporates three separate CRTs,
representing green, red, and blue outputs. Each CRT uses an independent deflection/convergence yoke,
magnetic centering ring, coupler, C-element lens, and output lens (A/B lens). Each tube is mechanically
fastened to a coupler which houses fluid (a glycol-type substance) used to cool the high temperatures
generated by the small (7") CRTs. The fluid also provides an optical characteristic supporting the optical system
of the PTV. When replacement of a CRT or optical component is required, caution must be exercised in
preventing fluid spillage. The technician must carefully reassemble the CRT/optical components, ensuring a
proper seal of the coupling fluid. Use only factory original coupling fluid.
Caution: Do not use or add water as an alternative to the prescribed coupling fluid.
The following procedure should be used when performing repairs on the CRT/optical assemblies of the
Projection TV.
Note: Upon completion of CRT/optical assembly repair, the centering, convergence, gray scale, mechanical
and electrical focus adjustments are required. If more than one assembly requires repair, it is recommended the
service technician fully complete one assembly at a time, using the existing assemblies as a reference for the
alignment of the centering and convergence. |
ACEC
