How can you edit a post on this system?
Have you replaced the battery yet? Should do that first and reboot the scope several times to get the ram initialized.
Pay attention to the adjustments section, especially the power supply and beam (grid bias) adjustments.
What are the _exact_ low voltage measurements?
The ripples shown on your pictures all look good.
Can you measure the -2.7 kV line safely? That can be accessed by looking at the cathode or filaments on the CRT.
Does the Beam finder button do anything?