msg wrote in
:

PeterD wrote:

On Sat, 05 May 2007 22:14:57 -0500, msg wrote:

snip


I would really
appreciate a report of the behavior on a working 7600 series scope
when the readout board is disconnected; the service manual describes
various voltage measurements with the board removed so it is
permissible to do so and power the instrument (but no mention is
made of the scope's behavior with the board removed).

snip


Post what options were sold as part of this scope. Some were sold
without readouts, the fact there are no connectors indicates that
possibly the readout option was deleted.

Digging through Internet archives this morning I noticed a few posts
from folks seeking the readout board for 760x scopes with a mention
that 'Option 01' was a cost-reduced version sans this board so evidently
the scope should work without it (if properly optioned?). I was not
sure if any cable modifications would be needed if the board were
removed from a scope not-so-optioned.

And indeed I now discover an "Option 1" label on the bottom of the
left bay so this scope never had the board.

Its problems are elsewhere.

Thanks,

Michael


#1 check power supplies.
the LV regulator board at the top rear of the scope had problems with the
TO-3 connections to the PCB;the solder joints would crack and cause
intermittents,also the DIP socket was removed and the IC soldered direct to
the PCB. The cap-rectifier board had electrolytics go bad and cause voltage
problems.

I used to dismantle the LV reg assy,unsolder all the 6-32 studs for the TO-
3 xstr connections,file off the chrome plating down to the brass,and
resolder,and they would be much more reliable.


also,there's 4 electrolytic caps on the interface board that can cause Ps
problems.

Then there's the "gold-dot ribbon cables" that were a cause of
intermittents;the TEK-mod was to replace all the ribbon cables with new
ones that did not have the "gold-dot" connectors. G-D connectors are a
paler color than the good gold-plated connectors. Since you cannot get new
ones anymore,you would have to rework or build new ribbon cables.( a real
project!)

--
Jim Yanik
jyanik
at
kua.net