FR series Amplifier ribbon replacement instructions (NEW! IMPROVED! July 2000)
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Models affected:
FR series M1200, M1400, M1400i
M1200:
All models.
M1400i:
Before Serial # DA20889 and all models with “AM” prefix.
M1400 and 230v versions:
Before Serial # DB12700 and all models with “AH” prefix.
Add this as part of your normal repair procedures.
Note: This bulletin replaces all previous ribbon bulletins.
Symptom:
Ch.1 or 2 output signal intermittently fades out, or cuts out completely and/or the DC supply rail fuses blow.
Possible Cause:
The two ribbon cables from the input board may be defective
Solution:
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Replace the input ribbon cables with an improved type in all of the above models, (including any which
have had the previous ribbon bulletin completed).
Safety Warning:
Caution! These instructions are for use by qualified personnel only. To avoid electric shock, do not
perform any servicing unless you are qualified to do so. Refer all service to qualified personnel.
Tools Required:
Phillips screwdriver, Torx and Allen drivers, needle nose pliers, safety glasses.
Parts Required:
040-359-00
Ribbon cable, 28GA, 20 Pin, Length 4.25”, PLZD
Quantity = 1
040-360-00
Ribbon cable, 28GA, 20 Pin, Length 18”, PLZD
Quantity = 1
400-077-00
20 Pin Headers
Quantity = 2
Procedure:
1.
Remove all cords (including the power cable and speaker outputs) from the amplifier.
2.
Take off the top cover and inspect the ribbon cables. If they are not marked 040-359-00 or
040-360-00 then proceed as follows:
Remove the input board:
3.
Undo the XLR screws, TRS nuts, and pull out the four pot knobs.
4.
Disconnect the short ribbon cable from the amp board, and the long cable from the front panel
display board. On later amplifiers, you will have to remove the front display board first.
5.
Disconnect the black ground wire from the amp board.
6.
Undo the four screws on the right side of the chassis. This will give enough room to pull out the input
board. Catch the two metal XLR plates before they fall inside (not present on later amplifiers).
Ribbon modification SSE July 2000
Ribbon mod.pdf, page 1 of 2
Ribbon
Ribbon
Input
board
Continued....
XLR plates
