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FINDING THE PROBLEM:
You will need to have a multimeter available to proceed with the following
procedures. Pushbutton S1 MUST be pressed in order to make voltage
measurements. If a resistance measurement is indicated be sure to remove
the battery before making the reading to avoid damage to your meter. You
may need to refer to the schematic and board layout to determine the exact
location of the test points. Readings will be indicated in the brackets, "[xxx]" ,
in the text below. The readings should be within the range indicated. Make
sure you have a fresh 9 volt battery installed for the voltage readings. Con-
nect the black or negative lead of your meter on the "-" connection of
the battery at the black wire from the battery on the board unless other-
wise instructed.
If you find that a measurement is not as expected, or if everything looks right
but it still doesn't work, stop and go to the "WRONG MEASUREMENT(s)?"
section for help finding the problem because any further readings may be
wrong because of the problem.
PROBLEM:
The 315MHz, 120KHz and 20KHz indications stay on all the time
If you have used a cleaning solution to attempt to make the board look
pretty you should call us. The use of cleaning solutions with No-Clean
solder fluxes can cause the input amplifiers in U1 to have problems
due to the high input impedance and gains involved.
A good check for this is to measure the voltage on the "+" and "-" input
pins, (U1 pins 2 and 3 for example), on one of the problem stages.
With no signal present the voltages should be less than +/- 10mV,
(0.010V), with reference to the "virtual" ground between R22 and R23.
If the levels are any higher than this the problem could be caused by
the use of a cleaning solvent.
If you think this is the case please contact our tech support depart-
ment at 585-924-4560 and we will try help you.
PROBLEM:
Nothing happens when the "PRESS & HOLD TO TEST" button is pressed
Measure the voltage at the following points.
WRONG MEASUREMENT(s)?
Make sure you have a fresh battery. Then make sure C3, R22,
R23, R7 and D1 are the correct values and properly installed .
"+" connection of the battery , [+8.5V to +9.1V].
Connection between R22 and R23 , [+4.5V to +5.2V].
WCT3 28
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