Troubleshooting Ic Opamps; Technical Support - Orban OPTIMOD-FM 5500 Operation Manual

OPTIMOD-FM DIGITAL
I) Click the "Advanced..." button on the "Internet Protocol (TCP/IP)" Window.
J) In the "Advanced TCP/IP Settings," select the "General" Tab; make sure that
no check boxes are checked.
K) Click "OK" to dismiss the "Advanced TCP/IP Settings" window.
L) Click "OK" to dismiss the window whose name is your new connection.
M) Restart your computer. (This resets the serial port and reduces the likelihood
that you will encounter problems connecting to the 5500.)

Troubleshooting IC Opamps

IC opamps are operated such that the characteristics of their associated circuits are
essentially independent of IC characteristics and dependent only on external feed-
back components. The feedback forces the voltage at the (–) input terminal to be
extremely close to the voltage at the (+) input terminal. Therefore, if you measure
more than a few millivolts difference between these two terminals, the IC is proba-
bly bad.
Exceptions are opamps used without feedback (as comparators) and opamps with
outputs that have been saturated due to excessive input voltage because of a defect
in an earlier stage. However, if an opamp's (+) input is more positive than its (–) in-
put, yet the output of the IC is sitting at –14 volts, the IC is almost certainly bad.
The same holds true if the above polarities are reversed. Because the characteristics
of the 5500's circuitry are essentially independent of IC opamp characteristics, an
opamp can usually be replaced without recalibration.
A defective opamp may appear to work, yet have extreme temperature sensitivity. If
parameters appear to drift excessively, freeze-spray may aid in diagnosing the prob-
lem. Freeze-spray is also invaluable in tracking down intermittent problems. But use
it sparingly, because it can cause resistive short circuits due to moisture condensation
on cold surfaces.

Technical Support

If you require
http://www.orban.com/contact/
problem accurately. Know the serial number of your 5500  this is printed on the
rear panel of the unit.
Please check Orban's website, www.orban.com, for Frequently Asked Questions and
other technical tips about 5500 that we may post from time to time. Manuals (in
.pdf form) and 5500 software upgrades will be posted there too — click
"Downloads" from the home page.
technical support,
for contact information. Be prepared to describe the
contact Orban customer
TROUBLESHOOTING
service. See
5-13