You have done the first thing, take some good pictures. Now just
unplug those cables and see if you can get to those two parts to
attach some test clips. I would guess those caps have dried out if
the 55 volts is low.
You should be able to pull the whole assembly out for service.
Probable screwed down somehow. I don't have one of those units to
explore.
Good luck,
Regards
On 9/16/2022 11:24 PM, Radu Bogdan
Dicher wrote:
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Thank
you. I figured out that error, but I still can't figure out
how to access the measurement points. I enclose some pics.
Unless the PS PCB slides out somehow, I cannot yet figure out
how to access those points.?
Not
wanting to sound lazy, but I really hate
terrible?engineering of servicing. Jury's still out on
whether it's me not having read the entire service manual
(closely enough), or whether they did a bad job at making
these very serviceable.?
Radu.?
There is an error in the manual. A16 is actually A15, the
pass transistor assembly.? C1, C3, CR1, and CR2 are just
below the J2 and J3 connectors.
Regards
On 9/16/2022 9:00 PM, Radu Bogdan Dicher wrote:
Working on this unit, with a
non-working display, and other lights on there not making
much sense. I didn't even really try to output a signal
and see if it's there.?
PS a high profile suspect, obviously. All raw DC supplies
look OK, all regulated supplies are low by almost about
30%. Smoking gun that is.?
So, I am working through the troubleshooting steps for
Group F (p.8-F-1). If regulated supplies are off, and
unregulated are OK, step two says to check A16 voltage
doubler. This is supposedly done by measuring 55V between
R1/CR2 and R2/CR4.?
Has anyone in the history of the 3335A been able to reach
the points where measuring this is feasible? I've been
bending my probes and self to figure how am I supposed to
perform this measurement. Has anyone done this recently
enough to recall, or versed in this unit to tell me how
the heck am I supposed to measure this unreachable
potential differential?
Thank you,
Radu.?
