Ramsey Electronics PM10DC, Manual

Page: 36 / 40

PM10DC
y
36
TROUBLESHOOTING
PROBLEM: I get the same power in both displays all the time no matter the
load. If I reverse the connections, the same thing happens.
SOLUTION: There is a short circuit in your directional coupler. One of the bus
wires is probably shorted to ground preventing normal operation. Please in-
spect this area of your board for possible problems. Also use a voltmeter to
check your 50 ohm termination; it may have been destroyed by an accidental
high power transmission into it and you are trying to calibrate your meter using
something other than 50 ohms!
PROBLEM: The display shows me nothing.
SOLUTION: This could be a result of a variety of problems. The first thing we
will check is the contrast. Adjust R4 until you see something on the display.
The next thing we will check is the power source, so you will need a voltmeter
here. Check pin 8 of U1 for +5V when the power is switched on. If not, check
for solder bridges or opens. Also check your battery wiring and battery; make
sure the battery jack is installed in the correct orientation. The battery should
read at least 8V when the power is off.
If power tests fine but still no display, check the mounting between the main
board and the display board. You may have a short between one of the signal
lines and data cannot get to the LCD controller. Also check to make sure you
installed the display in the correct orientation.
PROBLEM: The display shows me power, but it is way off!
SOLUTION: This can be a problem, since calibration is dependant on the fact
that there aren’t a lot of strong signals in the vicinity of your unit while you are
calibrating. If you have a good signal generator you will want to set the gen-
erator output to +0dBm and turn R2 on the detector board so the display
matches it. If you are unable to find a good generator send the kit in to us, and
for a small fee (call us!) we will calibrate and test it for you.
PROBLEM: I just can’t make the &#^$^@! Thing work!
SOLUTION: Call Ramsey Support at 1-585-924-4560 or look at the warranty
in this manual. We are here to help, and reduce your frustration as much as
possible. It usually is something simple. Oh, please count to ten before calling
taking some deep breaths first… These DO work, I promise!