"bz" wrote in message
98.139...
Have had this 545 sitting, unused, for years, in my utility room. Bought
it
surplus for 50 bux about 20 years ago. IIRC, it 'used to work fine'.

I wheeled it into my ham shack last week, and turned it on. The trace was
too bright and would not turn down completely. After a few minutes, it
shut
down. Found that the FAN mounts had deteriorated and the cooling fan was
not turning. After making new fan mounts and digging lots of small pieces
of aluminum (from the fan hitting the filter) out of the scope, I turned
it
on again. Still too bright. Focus/astigmatism are poor also.

Beam blanking seems to be working as the spot goes away when there is no
sweep.

Checking voltages, the 220 volt test point on the upper right side is only
about 135. Other voltages (500, 350, 100, -150) are all good.


There's your starting point - if the power supplies are way off that can
cause a lot of problems. Get your 220 supply back within specs and see how
the scope works. From what I remember, the -150 is the reference supply
that the rest are set to.

Granted, there could be something elsewhere in the scope loading down the
220V power supply (leaky caps, etc.) but it's the place to start
troubleshooting.

Bob