MFJ MFJ-784B, Instruction Manual, Page: 67 / 74

MFJ-784B Instruction Manual
Appendix A-3
16. Test the T/R line by shorting pin 5 of the To Radio connector to ground
for approximately one second or until the LEDs blink. If it is shorted for
less than one second, the DSP might signal a false failure.
17. The filter EEPROM memory, IC U8, is then tested without assistance.
Note that this step will reset the CW sidetone and the Pre-Set data filters
to factory defaults.
18. If you've pressed the buttons, turned the switch and the knobs, placed the
jumpers, and grounded the T/R sense line in the correct order and the
unit is working properly, the unit repeatedly sends
OK-784 (with blinking
green LEDs) in Morse code. A repetitive message such as B4 FAIL (with
blinking red LEDs) indicates that you didn't follow the correct order or the
unit failed the test. The prefix and the number indicate the nature of the
failure (see table below).
19. Disengage the Power button and remove the power plug .
20. Replace all jumpers from JMP1 to JMP7 to their original positions.
21. Replace the DSP's cover (6 screws).
22. Reconnect power and resume with normal operation.
Prefix-Number and Its Designation
B1 = AGC button S1 = LR/HR switch position
B2 = PROGRAM button S2 = BP switch position
B3
= MEMORY button
S3
= 2BP switch position
B4 = MANUAL NOTCH button S4 = CW switch position
B5 = AUTO NOTCH button S5 = SSB switch position
B6 = NOISE REDUCTION button S6 = RTTY switch position
B7 = SPEAKER button * S7 = HF PACKET switch position
B8
= DSP button
S8
= AMTOR switch position
B9 = POWER button * S9 = PACTOR switch position
J1 = JMP1 jumper S0 = SSTV/FAX/WeFAX switch position
J2 = JMP2 jumper K1 = TUNABLE FILTERS left knob
J3
= JMP3 jumper
K2
= TUNABLE FILTERS right knob
J4 = JMP4 jumper K3 = NOISE REDUCTION knob
J5 = JMP5 jumper K4 = VOLUME knob *
J6 = JMP6 jumper TR = T/R sense -- TO RADIO DIN pin 5
J7
= JMP7 jumper
EE
= EEPROM -- IC U8
* These controls are included here for completeness even though they are
not directly tested by this self-test.