Hey Don,
Great first post, I'm sure you'll get the old girl up to snuff in no time.
Oscilloscopes are kind of unique in that it's often possible to diagnose
problems to a functional block by "milking" the front panel. If you haven't
already, I suggest you read through the "Troubleshooting Your Oscilloscope"
document ().
Regarding the 5V supply, you probably need to sort that out before you can
expect anything else to make sense. I can't pull the service manual right
now, but generally the LV supplies in these scopes are current limited, and
will have a dropper resistor somewhere in line with the main supply. By
measuring the voltage over the dropper resistor, you can see how much
current is going through, and whether the supply is in current limiting.
... time passes ...
The dropper resistor is R4325, a 1.2Ohm. It is supposed to drop 0.4V, so
the service manual expects 333mA out of the +5V supply. If the supply is in
current limiting, it may be hard to trace it to a cause, depending on how
easy it is to isolate blocks of the 465B - I've never worked on one.
Good luck,
Siggi
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On Mon, Feb 12, 2024 at 12:07?PM Don - AC2EV <dkiser100@...> wrote:
Ripple is within spec.
Why did I replace the capacitors?
1. It's relatively simple and cheap to replace them
2. I've had capacitor issues in other equipment. The biggest offender
being the Rifa caps in my other oscilloscope
I did suspect the CRT but given that the scope works in X-Y mode that lead
me down that route.
Why the pre-amp and sweep? This is where the manual lead me through the
troubleshooting so far. It may be the wrong path, but it's a path I can
follow to see where it leads.
