I’ve been using my Polyend synth for a week, and after unplugging and plugging in the audio input a few times today, suddenly there’s no sound, and there’s strong noise instead. how I should address it? I’ve tried a few things: 1. I updated the system twice. 2. I swapped the audio cable. However, nothing has changed after trying these steps.
There’s 2 things I would try first before opening a support ticket
Take out the sd card and put it in your computer and delete the work folder (it’ll remake it once you put it back in synth) and then put it back in synth and try again. Sometimes it gets corrupted
2nd thing, there is a reset button on synth (back up anything if needed before doing so). The info is in the manual but here is info too
"SYNTH AND FIRMWARE RESET
- Download the latest firmware. Access firmware updates for your device
from your registered account at Polyend. - Copy the downloaded .psf firmware file into the /Firmware folder. This
can be found in the root directory of the SD Card. Also ensure any
previous update files remain in the firmware folder. - Insert the SD card into Synth.
- Use a pin or thin object to press the internal reset button. This is located
on the rear of the device behind the case next to the USB connection. - Synth will reset and search the firmware folder on the SD Card. A
random firmware will be selected and installed in order to recover Synth
to a working state. The install process is typically less than 1 minute."
1 Like
Thank you for your response. However, I have also tried deleting the files and resetting the system, but the problem persists. I’m wondering if it might be an issue with the input interface, so I plan to take the device apart tonight after work to check it. Again, thank you for your help.
Please excuse this question if it seems stupid, I’m just trying to rule out possibilities: Did you happen to plug your audio cable into the MIDI out port instead of audio out? That at least give a lot of noise for me, when I accidentally do it 
2 Likes
Haha good thinking!
I had the same thought - I’ve done it a couple of times myself and thought my Synth was failing until I realised my error.
Unfortunately, I’ve checked the headphone jack, and it has always been correct without any mistakes. But thank you for your suggestion nonetheless.
1 Like
Alright. Are you using the power supply and USB cable that came with the unit? Did you try with another source of power? I wouldn’t be surprised if it makes weird noises in case it is under (or even over) powered.