hi chance,
Some ideas, if you havn't already tried them.
Check the astigmatism control setting.
Check the mains voltage selector is set for your local voltage.
Low EHT is quite often a cause of focussing problems, if the CRO has been stored in a damp environment, the EHT could be leaking away.
Turn down the brightness/intensity until you can just see the trace.
Leave the CRO running for a few hours, to see if its a dampness problem.
[until you have confidence in the CRO, don't leave it unattended during this test].
If this dosn't work, turn OFF the CRO and disconnect from the mains.
Leave the CRO off, for an hour or so, remove the covers and using a 100K
resistor in series with a grounding wire connected to the CRO chassis, discharge any point you want to touch/measure, BEFORE you measure.
Do a visual check, of the CRO, a wire/connector may have come off in transit.
Take CARE the voltages can be lethal, dont work alone when doing the following checks.
If you have the manual, get a EHT test meter and check the EHT, and at the
tube base check the Cathode and Focussing potentials.[ and heater voltage]
If these all check out, measure the tubes 'beam current' , refer to the manual
for the value [ in the order of 100 to 200 microamps]
If this is low then I suspect you have been sold a 'turkey'
Regards
EricG
Let is know how it goes.