I cannot find a circuit for a Yamaha P-45 but have found the service manual for a [https://elektrotanya.com/yamaha_p-115b_p-115wh_p-45b.pdf/download.html|Yamaha P45-B] which hopefully will be close enough to be of some help.
To download the file click on the “I am not a robot” checkbox and then select download. Be patient it takes a little while to find the file.
I don’t know about notes in music but looking at the circuit it appears that a +3.3V supply is fed to each note in the scale and when a key is pressed this voltage changes and the change is detected by the CPU and the appropriate note is played.
Since only the first 4 lower D notes don’t work it may be that there is a break in the wiring multiple or a loose connector to the section of the keyboard.
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''Check that the harness plugs between the GHL88M board Connector 1 and the GHL88L board Connector 1 are securely connected and that there is +3.3V appearing on the appropriate pins as shown below'' These boards may be directly below the keys
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''Check that the harness plugs between the DM board Connector 201 and the GHL88M board Connector 2 and the GHL88M board Connector 1 and the GHL88L board Connector 1 are securely connected and that there is +3.3V appearing on the appropriate pins as shown below'' The GHL88L, M and H boards may be directly below the keys
Here are some images where I have shown the location of the power supply circuit for the D notes.
click on images to enlarge for better viewing.
The power for the D notes is on wire N12
[image|1791203]
and leaves the DM board on Connector 201 pin 27
[image|1791205]
where it comes in on GHL88M (M for middle?) board Connector 2 pin 2 to feed the middle numbered D notes (D2-D4) and multipled to GHL88H Connector 3 pin 2 to feed the higher numbered D notes (D5-D6) as well as GHL88M board Connector 1 pin 17
[image|1791204]
where it connects to GHL88L (L for left?) board Connector 1 pin 2 to feed the lower numbered D (D0-D1) notes
I cannot find a circuit for a Yamaha P-45 but have found the service manual for a [https://elektrotanya.com/yamaha_p-115b_p-115wh_p-45b.pdf/download.html|Yamaha P45-B] which hopefully will be close enough to be of some help.
To download the file click on the “I am not a robot” checkbox and then select download. Be patient it takes a little while to find the file.
I don’t know about notes in music but looking at the circuit it appears that a +3.3V supply is fed to each note in the scale and when a key is pressed this voltage changes and the change is detected by the CPU and the appropriate note is played.
Since only the first 4 lower D notes don’t work it may be that there is a break in the wiring multiple or a loose connector to the section of the keyboard.
''Check that the harness plugs between the GHL88M board Connector 1 and the GHL88L board Connector 1 are securely connected and that there is +3.3V appearing on the appropriate pins as shown below'' These boards may be directly below the keys
Here are some images where I have shown the location of the power supply circuit for the D notes.
click on images to enlarge for better viewing.
The power for the D notes is on wire N12
[image|1791203]
and leaves the DM board on Connector 201 pin 27
[image|1791205]
-
where it comes in on GHL88M board Connector 2 pin 2 to feed the higher numbered D notes and multipled to GHL88M board connector 1 pin 17
+
where it comes in on GHL88M (M for middle?) board Connector 2 pin 2 to feed the middle numbered D notes (D2-D4) and multipled to GHL88H Connector 3 pin 2 to feed the higher numbered D notes (D5-D6) as well as GHL88M board Connector 1 pin 17
[image|1791204]
-
where it connects to GHL88L board Connector 1 pin 2 to feed the lower numbered D notes
+
where it connects to GHL88L (L for left?) board Connector 1 pin 2 to feed the lower numbered D (D0-D1) notes
I cannot find a circuit for a Yamaha P-45 but have found the service manual for a [https://elektrotanya.com/yamaha_p-115b_p-115wh_p-45b.pdf/download.html|Yamaha P45-B] which hopefully will be close enough to be of some help.
To download the file click on the “I am not a robot” checkbox and then select download. Be patient it takes a little while to find the file.
I don’t know about notes in music but looking at the circuit it appears that a +3.3V supply is fed to each note in the scale and when a key is pressed this voltage changes and the change is detected by the CPU and the appropriate note is played.
Since only the first 4 lower D notes don’t work it may be that there is a break in the wiring multiple or a loose connector to the section of the keyboard.
''Check that the harness plugs between the GHL88M board Connector 1 and the GHL88L board Connector 1 are securely connected and that there is +3.3V appearing on the appropriate pins as shown below'' These boards may be directly below the keys
Here are some images where I have shown the location of the power supply circuit for the D notes.
click on images to enlarge for better viewing.
The power for the D notes is on wire N12
[image|1791203]
and leaves the DM board on Connector 201 pin 27
[image|1791205]
-
where it comes in on GHL88M board Connector 2 pin 2 to feed the remaining D notes and multipled to GHL88M board connector 1 pin 17
+
where it comes in on GHL88M board Connector 2 pin 2 to feed the higher numbered D notes and multipled to GHL88M board connector 1 pin 17
[image|1791204]
-
where it connects to GHL88L board Connector 1 pin 2 to feed the lower D notes
+
where it connects to GHL88L board Connector 1 pin 2 to feed the lower numbered D notes
Hi,
I cannot find a circuit for a Yamaha P-45 but have found the service manual for a [https://elektrotanya.com/yamaha_p-115b_p-115wh_p-45b.pdf/download.html|Yamaha P45-B] which hopefully will be close enough to be of some help.
To download the file click on the “I am not a robot” checkbox and then select download. Be patient it takes a little while to find the file.
I don’t know about notes in music but looking at the circuit it appears that a +3.3V supply is fed to each note in the scale and when a key is pressed this voltage changes and the change is detected by the CPU and the appropriate note is played.
Since only the first 4 lower D notes don’t work it may be that there is a break in the wiring multiple or a loose connector to the section of the keyboard.
''Check that the harness plugs between the GHL88M board Connector 1 and the GHL88L board Connector 1 are securely connected and that there is +3.3V appearing on the appropriate pins as shown below'' These boards may be directly below the keys
Here are some images where I have shown the location of the power supply circuit for the D notes.
click on images to enlarge for better viewing.
The power for the D notes is on wire N12
[image|1791203]
and leaves the DM board on Connector 201 pin 27
[image|1791205]
where it comes in on GHL88M board Connector 2 pin 2 to feed the remaining D notes and multipled to GHL88M board connector 1 pin 17
[image|1791204]
where it connects to GHL88L board Connector 1 pin 2 to feed the lower D notes
[image|1791206]