[GreenKeys] ASR33 debugging

[Hugh Pyle]

The selector driver is the FS-1 Receive schematic here:
http://www.bitsavers.org/communications/teletype/33/Model_33_Schematic_Jun75.pdf

Q2 is the heatsink-mounted TO3 case.
R5 (8 ohm, 5W) often overheats.  So I'd start by removing the card and
looking for lifted or broken traces due to heat damage.



On Mon, May 20, 2019 at 11:55 AM Bob Coggeshall <bob at cogwheel.com> wrote:

> Hi Folks
>
> I've got an ASR33 whose selector magnet stays energized all the time with
> nothing connected to the P2 Connector. I think the drive circuitry might be
> blown out.
>
> I've been trying to decipher where those components are from the
> schematics http://tty.nerdology.org/schematics/
> But they are notoriously clear as mud.
>
> Any pointers on how to debug the selector magnet driver ? TIA
> ..c
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