ASR-33 question

From: Chuck McManis <cmcmanis_at_mcmanis.com>
Date: Sat Jun 19 19:06:37 1999

At 12:08 AM 6/20/99 +0100, Tony wrote:
>This is what we used to call 'spacing out', I believe. The receive
>electromagnet is deenergised (for some reason - it shouldn't be), so the
>receive cluth free-runs, etc.

Sounds like a good name.

>If it's doing it in local mode, check :
>
>1) The local loop PSU (the transformer + rectifier + multi-tapped
>resistor in the call control unit chassis)

No CCU on this model, but I'll check this.

>2) The transmit distributor (PCB + spinning contact in the rear right of
>the main chassis). It should be stopped. And there should be continuity
>between the 2 wires on the schematic that are obviously the transmit loop.

Uh oh. It is spinning.

I'm trying to test this without the '8 plugged in for the moment. Should I
hook up some sort of bypass on the loop interface?

>3) The selector magnet driver (the little 'module' in the call control
>unit, consisting of a PCB + power transistor + ...).


>4) The line/local relay contacts in the call control unit.

This seems to work ok, when I switch it from local to line it settles down.

>Well, is the transmit shaft (rear right, with the distributor brush on
>the end) turning? If so, then either it's stuck in here-is (in which case
>the here-is drum behind it will be turning), or the keyboard is trying to
>send something (check that the main chassis is correctly seated, that the
>H-plate between the keyboard and the main chassis is fitted properly,
>etc).

Here-is Drum is not turning but the tranmit shaft is. I'll have to check
the "h-plate" Now to find it on the parts diagram...

Thanks Tony,
--Chuck
Received on Sat Jun 19 1999 - 19:06:37 BST