Zenith PRO 841x/851x

      >> Introduction 
      >> Layout and Setup Tips 
      >> Focus Block Replacement 
      >> CRT Tube Replacement 
      >> Manuals / Downloads 

Top View

Once the top cover is taken off of the set, you’ll see the main video processor board, the convergence board and the new style focus block controls. A part of the HV board is also shown in the top right corner.

The convergence board controls all of the analog convergence functions. There are a few master size/convergence controls found in the hidden service menu accessible via the remote control, described elsewhere here.

The video processor board controls all of the onscreen menu functions, control and converts the incoming video to the RGB signals that drive the CRT tubes. There are no adjustments on this board. Failure is relatively rare on these boards.