MFJ-441 Instruction Manual
SlimLine Econo Keyer
6
Self Test
A self test is included to perform testing of the paddle, the buttons, the controls, and the audio cir-
cuitry. At any time, turn off the power to stop the self test.
To perform this test:
1. Turn off the power and remove the power plug.
2. Push all buttons so they are in the out position.
3. Turn all knobs to full clockwise position, except the Volume control. Set volume to a comfort-
able listening level.
4. Remove the box cover (2 screws).
5. Remove jumpers JMP 4 to JMP 7. Set jumper JMP 3 to the "B" position. Set jumpers JMP 8 and
JMP 9 to the "H" position.
6. Reconnect power.
7. Squeeze the paddle while turning the power on. The self test starts by sending the copyright
message "COPYRIGHT 1996-199X MFJ ENTERPRISES, INC. VERSION X.XX" confirming the
audio circuitry is working properly. Release the paddle before the message is finished. For the
entire test, the LED should blink once after each operation. If the LED blinks continuously the
unit fails the test and a Morse code message is sent to indicate the nature of the failure.
8. The paddle, the Message button and jumpers JMP 3 to JMP 9 are automatically tested for
shorts to ground. The LED should be off at this point.
9. Press and release the dot level; press and release the dash level.
10. Press and release the Message button.
11. Lock in the Semi-Auto/Auto button, then press and release the dash level.
12. Test the Speed control by turning it to full counter-clockwise then to full clockwise. The LED
should blink once at each end.
13. Test the Weight and Tone controls in the same way. The LED should blink once at each end.
14. Test the jumper connections by placing the plug-in jumpers on the "A" position of JMP 3 and
then the "L" positions of JMP 4 to JMP 9 in ascending order. The LED should blink once for
each jumper.
15. When all is okay, a repetitive message "PASS" is sent to the speaker. A repetitive message such
as "SP FAIL" indicates that you did not follow the correct order or the unit failed the test.
16. Turn off the power after confirming the audio has good quality and remove the power plug.
17. Replace all jumpers to their original positions.
18. Replace the cover and secure it with the two (2) screws.
19. Reconnect power and resume with normal operation.
Failure Message Meanings:
DH FAIL Dash level is shorted or improperly connected.
DT FAIL
Dot level is shorted or improperly connected.
J3 FAIL
Jumper JMP 3 is shorted or improperly connected.
J4 FAIL
Jumper JMP 4 is shorted or improperly connected.
J5 FAIL
Jumper JMP 5 is shorted or improperly connected.
J6 FAIL
Jumper JMP 6 is shorted or improperly connected.
J7 FAIL
Jumper JMP 7 is shorted or improperly connected.
J8 FAIL
Jumper JMP 8 is shorted or improperly connected.
J9 FAIL
Jumper JMP 9 is shorted or improperly connected.
MG FAIL Message button is shorted or improperly connected.
SA FAIL
Semi-Auto/Auto button is shorted or improperly connected.
SP FAIL
Speed control is bad.
TN FAIL
Tone control is bad.
WT FAIL Weight control is bad.
