Noise in Tek 576 test

peter bunge

The performance check starts on page 5-4 and everything was perfect up to:
step 16. Check Horizontal and Vertical Displayed Noise on page 5-15.
The noise is twice what it should be for the horizontal and four times for the vertical.
Does anyone have an idea of what to do about it or where to look next? The manual says very little.
Power supplies have been 'scoped for ripple and are OK.