Layout and Setup Tips
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7 8 9 10
Video input board
The above board under the CRT’s is the video input board, with the deflection
processor located to the left, and the shielded board to the right under the
blue tube is the quad decoder. These boards are hard to service by the end user.
There are many revisions of these boards, and most will not interchange with
another. The input LED’s indicate which input is selected via the keypad. With
the late model 708 board pictured above, most components are of the surface
mount type and cannot be removed without special tools. Failure of the
deflection processor can cause a ‘no picture’ condition with no fault LED’s
being lit. Ditto for a bad video board or quad decoder.
The CRT sockets shown above house the video output section for each CRT. All
three are identical and can be swapped to determine whether a video output card
is bad. Note that the multi-pin plug in connectors onto the video board bend pins
very easily, and more than one ‘dead’ video output board has been due to a bent
connector pin on the motherboard.