Yamaha P-115 turn on but No sound - Doesn't turn off

[DAIGS]

Hi,
I need to repair a P-115 yamaha digital piano with a strange behaviour.
When I power on the piano from the dedicated on/off switch, the power led go to ON (red led), but the keyboard doesn't produce any sound, nor in the speakers nor in the headphones.
When I try to power off (pressing the switch for at least 1 second), the keyboard doesn't power off, the red led remains ON. I need to unplug the adapter cable to switch off the keyboard.

I checked the 12V voltage rail on the input PCB, after the power plug and it is OK.

I checked also the power switch on the dedicated frontal panel pcb with a multimeter and it works fine (when pressed 0 ohm, when released open circuit).

I tried to enter in test mode as described in the service manual, but the keyboard seems not to enter in that mode (C#2-F2-G#2 pressed at the same time and power on the piano, should follow a sound).

How do you suggest to proceed?

P.S. I posted also on badcap forum but with no luck.

Thanks a lot.

 

[jthiruvady]

Hi,
I need to repair a P-115 yamaha digital piano with a strange behaviour.
When I power on the piano from the dedicated on/off switch, the power led go to ON (red led), but the keyboard doesn't produce any sound, nor in the speakers nor in the headphones.
When I try to power off (pressing the switch for at least 1 second), the keyboard doesn't power off, the red led remains ON. I need to unplug the adapter cable to switch off the keyboard.

I checked the 12V voltage rail on the input PCB, after the power plug and it is OK.

I checked also the power switch on the dedicated frontal panel pcb with a multimeter and it works fine (when pressed 0 ohm, when released open circuit).

I tried to enter in test mode as described in the service manual, but the keyboard seems not to enter in that mode (C#2-F2-G#2 pressed at the same time and power on the piano, should follow a sound).

How do you suggest to proceed?

P.S. I posted also on badcap forum but with no luck.

Thanks a lot.

Having the same issue. Did you able to fix it?

 

[libertine]

I have this same issue on my P-115 as well and no confirmed solution either, but I do have a hunch.

Basically on the page 60 of the service manual, there is a list of test points on the DM board. Number 5 (labelled RES on the board) is the CPU & memory reset signal test point. Apparently, this point might reveal a problem with the IC4 on the board, which according to the parts list should be a R3112N291A-TR-FE voltage detector. I believe that that IC may very well be the issue or at least near where the issue arises on the board.

However, I don't have my keyboard opened up right now to confirm it.