Instruction manual

DCI1 • 24
TROUBLESHOOTING GUIDE
If your DCI1 does not work at all, recheck the following:
• correct orientation of U1 and U3 (see PC board Parts Layout Diagram)
• correct polarity of all electrolytic capacitors.
• correct orientation of all diodes (especially D1).
• all solder connections
• jumper wires at all JMP locations.
Still having trouble?
While we had hoped that it wouldn’t come to this, if you are still having trouble
with your DCI1, here are a few additional suggestions.
PROBLEM:
The Power LED (D9) doesn’t light and VR1 gets very hot quickly.
SOLUTION:
You likely have a short across the power supply or you have a
component placed in the incorrect orientation. Check all of your parts to make
sure they correlate with those on the Parts Layout Diagram.
PROBLEM:
The Power LED (D9) doesn’t light and VR1 remains cool.
SOLUTION:
Using an oscilloscope or a frequency counter to verify that there
is a 3.579 MHz signal on pin 7 of U3 and pin 3 of U1. It should be
approximately 0.5 Vp-p or greater. If you cannot check the oscillator, verify
that 5 Volts DC is present on the IC power pins (U1:5 and U3:18). If not, check
VR1 for 5 VDC output with at least 12 VDC input from your power supply.
PROBLEM:
It seems to be missing key entries when I try to enter commands.
SOLUTION:
Wait until after the confirmation tones have stopped before enter-
ing new commands. This is most common when controlling the J4 relay output
due to the amount of time it takes to provide the four feedback tones telling
you which device is about to be controlled.
PROBLEM:
My answering machine hangs up before I finish my commands.
SOLUTION:
Some answering machines will hang up automatically if they do
not sense any voice activity. Try talking into the phone at the same time to
provide the needed audio for it to hold the line. Example: Say “relay #1 ON” at
the same time you are typing the commands. Some answering machines may
not be compatible.