If you are one of the list members who believes that all
should be maintained as close to factory stock as
please just skip all that follows.
Measuring the current ramp via resistor R907
will show if the
transformer inductance is low. The current ramp
should be linear
without any curvature which would indicate that
T906 is saturating.
This brings up an interesting possibility. If the
inductance was low because of damage, then the
limiting implemented via pin 16 of the TL594 could
cause what looks
like unstable operation and Q9070 or CR907 could
run hot and fail
because of high peak current.
Several years ago I found myself with a couple of total
A 2213 with that ~!!@# current limiter and T906 both gone
and a Epson
printer with a bricked print head.
It dawned ( literally at dawn after one of my normal
sleepless nights ) on me that
both happened to have a 42 volt SMPSs.
I really had nothing to lose so I tried patching the Epson
supply to the 42 volt section of
the 2213, set my electronic circuit breaker to two amps and
hit the start button.
The scope returned to the land of the living.
I then cobbled er.., a.., installed the Epson PS into the
scope and it went back out into
"hell on earth" otherwise known as machine shop floor and
field service calls.
It was doing fine at least up until it was stolen from a job
site several months later.
At the very least it gave my 465B and 465M scopes a little
bit of rest.