Hi,

I bought a used USRobotics model 5686 external 56K modem. This one has
8 dip switches for setting various modes. This modem powers on and
only the "CS" led glows. Windows 95, 98 computers can't detect it. I tried
two new modem cables. I connected it to an older computer with "Telix" (Dos
based) and used the init string that was listed in a file on the CD rom, but
still no communication. Also, an "ATZ" sent to the modem, returns no
response. What is the most likely defective part in this modem?

Thanks in advance, Brad

Before you type your password, credit card number, etc.,
be sure there is no active key logger (spyware) in your PC.

Be sure and check to see that the serial ports are enabled in your CMOS.

Patrick

"Brad" <bpetria@verizon.net> wrote in message
news:40f3d108.676895@news.bellatlantic.net...

On Tue, 13 Jul 2004 13:56:57 GMT, bpetria@verizon.net (Brad) put
finger to keyboard and composed:

Before deciding that your modem is brain dead (failed flash?), I would
first verify that there is nothing amiss with its power supply.

I would use a multimeter to check for the presence of +12V and -12V at
the 25-pin serial connector. Measure pins 3,5,6,8, and 22. Use pin 7
as your ground reference.

Is your modem similar to this one?
http://home.tallships.ca/mspencer/usr56k.gif

If so, then measure the voltages on the pins and case of the large
device just below the power socket. I believe this could be a +5V
regulator, or maybe even +3.3V.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.