In this case, it is not?the straight forward measurement you envision.
The -8 volt supply does not directly reference to ground. Also, it is NOT a
random process. The first step I recommended was to take an ohmmeter reading to
ground of the -8 volt test point. Since he measured 50 ohms or so, that meant
that there were no directly shorted tantalums.
?
Again, it is a simple linear supply and easiest to check the items most
likely to fail. The bulk capacitor, the bridge rectifier, and the op-amp. Next
would be the pass transistors and the current limit circuit.
?
?
Regards,
Tom
?
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----- Original Message -----
Sent: Wednesday, January 16, 2013 4:30
AM
Subject: [TekScopes] Re: 465B
Oscilloscope No -8V
?
Just randomly desoldering caps will not bring you anywhere (or just with
luck). Have you checked the voltage and ripple before the regulator? If this
is fine you know that the bug's in the regulator or later in the chain. If not
you know it's in the transformer/rectifier/filtering
cap.
Samuel
