Are you sure that the 3rd lowest octave E note is also faulty?
Looking at the wiring diagram from the service manual, the B - Flat key (shown as A# in the diagram) and the E key share the same two wires back to the CPU board (DM board) (my PC doesn't let me type music note symbols i.e. Alt+9837 doesn't show "flat symbol)
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The reason I asked is that the bottom 3 octave A# keys and the bottom 2 E keys are located on the GHL88L board but the 3rd lowest E key is located on the GHM88M board and is directly multipled via a track on the board to the other E keys on that board whereas the lowest 2 E keys multipled to the other E keys in the keyboard via a cable connection between the two boards.
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The reason I asked is that the bottom 3 octave A# keys and the bottom 2 E keys are located on the GHL88L board but the 3rd lowest E key is located on the GHM88M board and is directly multipled via a track on the board to the other E keys on that board whereas the lowest 2 E keys are multipled to the other E keys in the keyboard via a cable connection between the two boards.
Check that the cable wires/plug connections on GHL88L board CN1 connector pins 4 (n14) and 10 (n24) and GHL88M CN1 connector pins 14 (n14) and 8 (n24) are OK
Here are some images from the service manual (see link in the Chosen Solution above) that may help.
Hi @donbfullavit
Are you sure that the 3rd lowest octave E note is also faulty?
Looking at the wiring diagram from the service manual, the B - Flat key (shown as A# in the diagram) and the E key share the same two wires back to the CPU board (DM board) (my PC doesn't let me type music note symbols i.e. Alt+9837 doesn't show "flat symbol)
The reason I asked is that the bottom 3 octave A# keys and the bottom 2 E keys are located on the GHL88L board but the 3rd lowest E key is located on the GHM88M board and is directly multipled via a track on the board to the other E keys on that board whereas the lowest 2 E keys multipled to the other E keys in the keyboard via a cable connection between the two boards.
Check that the cable wires/plug connections on GHL88L board CN1 connector pins 4 (n14) and 10 (n24) and GHL88M CN1 connector pins 14 (n14) and 8 (n24) are OK
Here are some images from the service manual (see link in the Chosen Solution above) that may help.
[image|3025976]
[image|3025977]
(click on images)