tektronix 465 question

[keithcc]

I just bought a tek 465 scope on ebay, but am having a problem with it.
For about half the time, everything works fine, but occasionally, and
for no apparent reason, the scope will behave as if there is no
incoming signal on either channel - time/div, horizontal position,
intensity, etc can be changed, but vertical position cannot be, and
nothing will display on the crt when a signal is applied to either
channel. During such periods, setting A Trigger Source to a channel and
then pressing the trig view button correctly displays the signal on
that channel. Furthermore, and perhaps irrelevantly, the AC/GND/DC
selector below CH 1's volts/div knob doesn't click like CH 2's
does.
The problem seems like it might be minor - a loose connection somewhere
- since at times the scope functions exactly as it should. any
suggestions as to what could be wrong are very much appreciated - i
don't have much experience with scopes, and certianly not with
troubleshooting them. I also don't have a service manual yet, but am
trying to find one on ebay. Thanks.

 

[tekamn]

do as Jim proposed: Clean the contacts and of course the rest of the
o'scope (cause iif it's put away the housing, that's easy to do in one
action).

and chck for bad caps in the LV supply -- electrolytics easily get
dried out in these scopes during the years.

After doing this maintenance, the scope should still work when used
occasionally when you will be long gone. The 465 are realy nice and
affordable nowadays.

hth,
Andreas