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James Sweet
 
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Default Tektronix 466 Scope Problem


"Chris" chris1@oupower_dot_com wrote in message
m...
Hi guys. I'm hoping that some of the more Electronics oriented
individuals out there may be able to help me. I am pretty much self
taught when it comes to electronics so my knowledge is very limited. I
always try my very best to troubleshoot and fix things when I have a
problem and believe it or not, I'm successful about 90% of the time.
Mainly it's because I can see the "burned" part or "hair line"
fracture in the solder board.

Well my Tektronix scope was something I purchased from e-bay about 2
years ago. It worked perfectly from what I could tell. I was very new
to scopes and didn't have any experience running them. My friend came
over one day and was like "oh yeah I can show you how to run a
scope... bla bla."

To make a long story short during a calibration discussion he
suggested we simply test the AC "house current" for the 60 cycles per
second that it should be. I don't remember exactly how we connected
the probes to the AC but when I made the final connection the circuit
breaker popped and I looked at him with a rather "****ed off"
expression.

I was sure my scope was ruined. I reset the breaker and turned the
scope on. It worked fine ..."See it's ok" my friend said! About 10 or
15 seconds later my scope went into a rather "dead" state. -Needless
to say I was ****ed. I take pride in all of my equipment ...no matter
how old it is. I take good care of it and try to learn as much as I
can with what I have.

We checked the fuses and they were both fine in the scope. He then
said ..."I'll take it to work dude. My buddy Hank at work fixes these
things all day long. He'll have it up and running in under 10 minutes
I bet." Needless to say about 4 months later I got it back ...still
broken. All Hank told my friend was something about the DC power
supply? I assume that means that one of the full wave bridge
rectifiers is bad? -But if that's the case why didn't he find which
one and replace it?

Anyway, from what I can tell, by turning the scope on for several
seconds here is what DOES come on: The lights on the front light up.
The trace dots do come up after a few seconds on the screen, but they
do not move. They get so bright (maybe because they are not moving?)
that I turn the scope off quickly in fear of it burning something
further out.

The fan on the back DOES NOT run anymore and the time portion does not
appear to work since I see only 1 bright or 2 bright dots in the
center (I think it's 2 of them).

I am willing to try or test anything you can suggest to help me fix
this. Please help if you can

Thank You,
-Chris


Sounds like one output of the power supply is dead, you'll need to do some
testing, do you have a multimeter? Turn the brightness way down, the static
dot will burn into the tube quickly.