Hi Anthony,
AJA> Does anyone out there have a BocaModem model M1440E external modem?
AJA> ...there's no wall cube to provide power. ...no specification...
DB> If you havta guess, it's prolly 12vdc; I've seen a few 9vdc. The
DB> thing is to figure out which is ground. You might see a diode...
I have no Boca but i had four external MoDems and none of them used
D.C. power. It seems quite possible you can find no polarity because it
doesn't have any. As you may know, an RS-232 serial-port interface will
call for a bipolar +/- 12 Volts internal power supply and achieving that
with an A.C. power input is easy (cheap)... Charge pumps weren't always
popular and being a 14K4 bps, chances are it will need an A.C. supply...
Looking at the internals for signs was a good idea and the polarity
markings, like those on a large electrolytic capacitor, especially, will
help. But i have a hint you should search for a diode bridge, the later
has the form of a 4 pins black rectangle with + and - markings and maybe
two more which are often labeled as "~" (tilde, the A.C. sign). I would
believe it's misleading to go through a succession of D.C. supplies with
increasing Voltage outputs when the MoDem requires A.C.: you'd conclude
that the appliance isn't receiving enough power while the bipolar RS-232
circuit, in particular, is simply failing because there's current on one
side only. Sometimes no 4 pins rectangle can be found but the rectifier
bridge is still there, as 4 discrete diodes. I'd try 9 V A.C. 1st. ;-)
Salutations,
Michel Samson
www3.sympatico.ca/bicephale
a/s Bicephale
... DOS+TCP/IP+TelNet+ZMoDem/Kermit+.QWK technologies for XTs or better!
To unsubscribe from SURVPC send a message to [EMAIL PROTECTED] with
unsubscribe SURVPC in the body of the message.
Also, trim this footer from any quoted replies.
More info can be found at;
http://www.softcon.com/archives/SURVPC.html
