This is the "classic" error and self test failures of a bad NVRAM. The NVRAM is a 28 pin "IC" with a built in battery backup. The original part in the 1988-89 oscilloscopes is a Dallas Semiconductor DS1235Y-200. This can be replaced with a Dallas DS1230Y. In my case the date code of the failing NVRAM was 1988 and I replaced it with a 2011 date code DS1230Y from Mouser.com. This part costs around $14. What I would call the "trick" to wake up the memory after installed, is to load the default cal setup. This helps the new ram to recognize the system. Then you will need to perform the self calibration, which uses the DC Calibration output on the rear panel input individually or all at once to the 4 input channels.
