[net.micro.cbm] Flakey 1670 modem

cuda@ihuxf.UUCP (Mike Nelson) (08/11/86)

*****
Note: I tried posting this once before and recieved no responses.  I 
wasn't sure that it made it out on the net.  If this is a repeat
please let me know so I can believe that the distribution option worked.
*****

I am having a problem with my 1670 modem.  The modem has always performed
well but seems to have a thermal problem with the speaker.  Example:
I plug the modem in and turn on the computer, dial the number and listen
to the ensueing tones and carrier until the modem cuts it off.  Work
for a couple of hours and then decide to call up another computer.  This
time enter the number and I can hardly hear anything coming from the
modem.  Then I wait, wondering if anything has really happened when up
pops the 'connect' and on I go again. 

The line is the first to go.  Sometimes I can hear the digit tones 
produced by the modem but not the dial tone or far end carrier.  You
can actually hear the thing fade during dialing.

My problem is this: The modem is usable, albeit annoying, so I really
don't want to send it in to get it fixed, but I can't figure out how
to get the case apart.  Is there anything I could do once the modem was
apart?  Is the part that monitors the line a standard production device?
Any comments would be appreciated.

ihuxf!cuda
Mike Nelson
AT&T Bell Labs

porter@cbmvax.cbm.UUCP (Jeff Porter) (08/18/86)

> 
> I am having a problem with my 1670 modem.  The modem has always performed
> well but seems to have a thermal problem with the speaker.  Example:
> I plug the modem in and turn on the computer, dial the number and listen
> to the ensueing tones and carrier until the modem cuts it off.  Work
> for a couple of hours and then decide to call up another computer.  This
> time enter the number and I can hardly hear anything coming from the
> modem.  Then I wait, wondering if anything has really happened when up
> pops the 'connect' and on I go again. 
> 
> The line is the first to go.  Sometimes I can hear the digit tones 
> produced by the modem but not the dial tone or far end carrier.  You
> can actually hear the thing fade during dialing.
> 
> My problem is this: The modem is usable, albeit annoying, so I really
> don't want to send it in to get it fixed, but I can't figure out how
> to get the case apart.  Is there anything I could do once the modem was
> apart?  Is the part that monitors the line a standard production device?
> Any comments would be appreciated.
> 

This sounds like a software problem.  

If the software you are using sends out an ATM0 (or whatever the
command is to turn off the speaker) then the modem will act just
as you have described.  

I constantly call multiple computers at any one sitting with my
128 and 1670 and don't have this problem.

Before dialing the second number, try typing ATZ to reset the
modem.  Then ATE1 to turn on echo.  This should give you the
same results as if you had logged in the first time.

Jeff Porter
Commodore Engineering