I'm still struggeling with my 2710. The biggest problem
is the schematics. I found a service manual ( and uploaded
it to bama and KO3BB because it is hard to find. But the
schematics are very hard to read. It is not a great copy,
but better as nothing.
Does someone has a good manual or readable schematics. Or
better a real paper manual for sale. ( I have a 2712 too,
that is working great but probably needs some new caps too
soon)
I replaced all caps, a lot were bad. I changed a dozen 1
uF tantaliums, they were leaking around 10-20 uA,, lost
some capacitance (10-40 %) and D was 0.4 to over 1.5. I'm
out of stock so I have to order new ones. In the mean time
I'm tracking the problems. No readable readout, a raster
of spots on the graticule and no response to signals, not
even the internal reference. It reacts on all buttons,
seems to pass the selftest ( it beebs like the 2712 when
done but I can not read if that is thru.
It looks at this moment the problem is in the storage
display board or microprocessor (commands not reaching the
other parts of the SA) board. A lot of work. I have no
extenders so i must solder short wires to the IC pins to
clip a probe or pod to. Look for truth tables of the 74
logic and look if the gates all work. And guess about the
PLS things ( a friend helps with that) And work my way
from PLS and gates through the board.
And if it turns out to be a PLS, eprom or other digital
thing i may have a problem ( but that friend maybe can do
things in that area, he is ( in my analog eyes) a real
digital wizzard )
Fred pa4tim
