MFJ-939 Plug&Play IntelliTuner Automatic Antenna Tuner
Instruction Manual
2006-2015 MFJ Enterprises, Inc.
29
number of times the green LED blinks for X and the number of times the red LED blinks for Y.
For example, green LED blinks one time and red LED blinks two times represent firmware
version number 1.2. This is also the test of the LEDs.
5.
Release the [TUNE] button. The unit then checks for short circuits, power-down detection level,
and wakeup circuitry.
6.
Press [ALT] button and the green LED should blink once.
7.
Press [TUNE] button and the green LED should blink once.
8.
The unit then tests its non-volatile memory. Notice this step will reset the unit to its factory
default settings.
9.
If the unit is okay, a repetitive message “PASS” will be sent as Morse code (di-dah-dah-dit di-dah
di-di-dit di-di-dit) and the green LED will blink. If there is a problem, a failure message will be
sent repetitively and the red LED will blink.
10.
Once you have confirmed that the audio is okay, turn the unit off.
11.
Wait one second and turn the unit on again to test the power-down detection circuitry.
12.
If the power-down detection circuitry is okay, a repetitive message “PASS” will be sent as Morse
code (di-dah-dah-dit di-dah di-di-dit di-di-dit) and the green LED will blink. If there is a problem,
message “PD FAIL” will be sent as Morse code repetitively and the red LED will blink.
13.
Turn the power off.
Failure
Message
Indicates
ANT FAIL
[ALT] button is shorted or improperly connected.
TUNE FAIL
[TUNE] button is shorted or improperly connected.
MEMORY FAIL
Non-volatile memory circuitry is improperly connected.
WAKEUP FAIL
Microprocessor wakeup circuitry problem.
PD FAIL
Power-down circuitry problem.
Table 9 Failure Messages.
Power-Down Circuit Test
When the 12 VDC power to the tuner is turned off, the tuner saves all settings to non-volatile memory.
The Power-Down Circuit Test checks the power-down detection circuitry. It is recommended that this test
be done immediately after the regular self-test described above.
Note:
The tuner must be reset to factory defaults before performing this test.
Here is the test procedure:
1.
Make sure power to the tuner is off.
2.
If the tuner has been reset to factory defaults, skip to step 6; otherwise continue with step 3.
3.
Press and hold
only
the [ALT] button while turning the power on. Both LEDs will blink until the
button is released.
4.
Within four seconds of releasing [ALT], press the [TUNE] button once.
5.
After releasing [TUNE] for four seconds, beep three times and turn the power off.
6.
Press and hold
only
the [ALT] button while turning the power on. Both LEDs will blink until the
button is released.
7.
Within four seconds of releasing [ALT], press the [TUNE] button four times.
8.
After releasing [TUNE] for four seconds and if the power-down detection circuitry is okay, a
repetitive message “PASS” will be sent as Morse code (di-dah-dah-dit di-dah di-di-dit di-di-dit)