My HP 54600B has been showing a horizontal and vertical calibration error message for some time when I turn it on.
I decided to replace the NVRAM, MK48Z18B-10 with a new one, encouraged by reading other posts that had done it successfully. To my regret, now the oscilloscope has died ( privilege violation : OH ) and does not respond to any key, so I cannot perform self-calibration.
I also can't find a way to perform a hard reset, if this is the solution. Any ideas?