[msg]

Greetings:

I just acquired a Tek 7603 scope with 7A18 dual-trace vert. and 7B53A
timebase plugins but upon internal inspection and cleaning discovered
that the readout board (when facing the front of the instrument it is
found on the upper right side midway along the length) is missing, as
are all interconnecting cables it uses.

The display is very corrupted: odd blanking and sawtooth displays
appear with no vertical input and horizontal sweep width changes with
timebase selection in a drastic way. A vertical input signal modulates
the strange displays in a fashion that suggests the vertical section
is functional and the vertical position controls do work.

The plugins are supposed to be in operating condition.

The internal logic timeshares the display between readout and
waveforms and is rather complex and implemented in Tek custom
hybrid ICs and a mix of TTL and CMOS. 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).

Many thanks to anyone willing to do this.

Regards,

Michael