Hello Guy,
I know this is a very general message but I think
it may help you... those HP multi-voltage
supplies usually have one of them as a reference.
If it is bad, all of them will show wrong
voltages. I am guessing the reference may be the
100V one (if I recall it right, on HP-141 series
it was that way, but of course they are ages appart)
Have you followed the Service Manual PS
troubleshooting section?. For sure it will be
clear there which one is the reference PS.
If I have some time later, I will check the 85662
Service Manual but now I am in a hurry and must
leave, so sorry for this so-generic message.
Good luck!
JOSE
At 10:31 27/08/2011, you wrote:
Hello group , I own an Hp8566B SA which went in
trouble suddenly ,the display disappear and the
instrument LED N¡ã1 still lit, I have checked all
the cables as state in the manual, and no
results,I have open the display unit and checked
the Power supply 100V is now 60 volts and the
-15V & +15V shows around 12V and -12V
respectively, what seems strange is that I see a
very high ripple at the output regulated and
nearly nothing like ripple at the input
unregulated. I cannot adjust the voltage ,and I
have checked the intensity to see if the
foldback section is not in action the intensity
is around 0.8A so no over current there.
The component of the power supply have been
changed as the pass transistor ,I have checked
the capacitors elko , ervery thing is good , checked also the esr,
any help will be very kind
I have posted photographs of my measurements in the photos
Cheers
ON1EV
Guy
--
73 EB5AGV - JOSE V. GAVILA - IM99sm La Canyada - Valencia(SPAIN)
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