I am getting the diagnostic error code+ E532X (E5321+ E5322+ E5323+ E5325) on my CSA803 or 11800-series oscilloscope. What does this mean?

I am getting the diagnostic error code+ E532X (E5321+ E5322+ E5323+ E5325) on my CSA803 or 11800-series oscilloscope. What does this mean?

Diagnostic error code E532X, indicates that during the power up self-test, the Executive Processor did not receive the expected pattern from Timebase board. This indicates a HW problem on either the Timebase or Executive Processor board.

Due to the age of these products, replacement parts are no longer available. Repairs on these products are available from Tektronix Service on a best effort basis.