Advantest TR4131 Spectrum Analyser Problem (Pt 1)

Bought this SA around 2yrs ago as a non-worker - history unknown. Although the display graticule and setting labels are displaying correctly changing in accordance with the controls.. there is no visible frequency trace or input signal. At certain settings of the reference & attenuator a vertical display becomes visible (with or without an input).. which exceeds the Y axis limits of the screen.

After testing all signals from first mixer onwards through couplers.. attenuator.. all LO's and IF's using my HP8595E all signals are present. Without any documentation I cannot be sure the power levels are correct.

[ifmatos]

Hi. I know it is being a very long ago but your video is the only one I found that shows the same problem my Analyzer have.. Ive looked everywhere to find info or to fix it with no sucess.. Did you find the problem on that Equipment ? Thanks