bonjour cher Monsieur
2336 is NOT 2465, and a blank screen is NOT normally a CRT issue.
1. get service manual for the serial number range see Tekwiki and w140.
2. Follow troubleshooting flowcharts
3. most of these decade's old scopes are still fine, most likely
a. use control,cleaner on all pots, contact cleaner on all switches except V/ div vertical
Exercise every control.
b. if no traces in TRIG AUTO, or BEAM FIND, suspect HV transformer and multipliers
c. HV test points are on HV shield area, and at cathode V, perhaps 1500...2200V.
Easy to check with a VOM and HV probe.
d. If the V or H out amps are bad the traces are deflected off screen, but visible in BEAM FIND
bon chance
Jon