Yamaha Motif Audio Issue

Hello All, I recently acquired a Motif Xs8 and it has some problems. The main one is white noise that almost completely masks the synth tones. The white noise is always present, but travels up and down as the volume fader is adjusted.

Problem #2 is no midi out. I was hoping if nothing else I could use it as an 88 key weighted midi trigger.

I am trying to ascertain if these problems are both related to the JA Board?
Thanks in advance!

I would look at the electrolytic Caps . in that area and check the voltage rails.

Can you set the MOTIF up to also get signal through the assignable outputs next to the Left/Mono Right outputs.

If you get the same “white noise” then the problem is most probably purely digital (see attached diagram ).

There is absolutely minimal amount of hardware involved after the DAC chips, ie IC 6 and IC7, and since the issue is on both channels then the problem being a capacitor is very remote since Left and Right have entirely different hardware.

Additionally I suggest you play with the unit and remove any effects or whatever has been assigned and make the sound as pure as possible to a piano sound. If the “white noise” still persists I would suggest a complete factory reset. If “white noise” still persist then it is most probably a memory issue - meaning a stuck bit that is continually “corrupting” the digital data stream causing the kind of “white noise” you are experiencing.

Aloha (I’m in Hawaii…lol) wernersaurus. The noise is present on all outputs, L/R, Assignable and headphone. Additionally the noise while always present, it gets louder and softer via the up & down of the volume slider. I have looked it over both internally and the schematic too, and came to the conclusion it was most likely digital, probably a bad DAC. Also I have no MIDI out. I was hoping at very least that I could use it as a weighted 88 key MIDI controller. Do you think that MIDI function could be affected as well. I looked through the settings and it looked like MIDI note on-off data should be going out, but nothing. So, I will try a factory reset and see if that clears it. That would be great.

I was considering changing the Audio/Jack board. If a reset doesn’t clear the problem, do you think it’s worth trying? ($172 for the board)

Mahalo for the info.

If you have same issue at both Left/Mono-Right and the Assignable Out it is NOT a DAC problem … Left/Mono-Right and Assignable Out use two separate DACs for each (see pic in previous post)

Do the reset and we see from there …

Ah, I wasn’t considering that when I briefly looked at the schematic. I’ll do that, possibly tomorrow & see. Thanks, Steve

Hello Werner. I finally got back to the Motif. Tried the factory reset. Problem unchanged.

Well, from here on need an oscilloscope at least to continue … since the signal is noise more than anything else we need to go backwards behind the DAC and look at the digital serial signal stream.

This transceiver needs to send the datastream through to the DACs - check the output signals and respective input signals

PIN 11 = Serial Data to Line Out
PIN 12 = Serial Data to Assignable Out
PINS 14, 16, 18 = clocks

… all of these are coming directly from IC010 SWP51 (MASTER) CPU

After that it’ll get hard … all else is happening inside the two CPU chips and associated ROM and RAM (Pic below - yellow bottom right is the two DACs - data follows straight to CPU)

I actually just thought of something else too; have you tried Firmware upgrade/re-install? Maybe you have a corrupted Wave ROM and re-installing the firmware may rectify it ??