My BOSS ME-25 is muted, no sound, the display is off, no LED is on.

Question edited to make some sense :>D

https://www.google.com/search?q=Cube+Baby+and+Boss+ME-25

..

Request the schematic diagrams from Boss.

https://www.boss.info/us/support/by_product/me-25/updates_drivers/
https://www.sweetwater.com/sweetcare/articles/usb-midi-device-not-recognized/
https://sourceforge.net/p/me-edit/discussion/1076568/thread/80898582/
https://sourceforge.net/p/me-edit/discussion/1076569/thread/5930eaa9/
https://www.guitarcenter.com/Boss/ME-80-Guitar-Multi-Effects-Pedal.gc

Boss ME-25, use polarity like boss stompbox.
+ voltage at the ring, and - voltage at the center pin, of the adapter
connector.
..
At ME-25 DC socket:

Is the power supply correct and power plug fully seated into the pedal? Are the other plugs the correct length and firmly seated?

USUALLY the Mute LED's for the switches ar operated by separate contacts on the mute switch an a resistor current limit for the LED. I could NOT find the schematic for this board, HOWEVER some Soundcraft brand mixers do NOT have illuminated Mute switches... Not sure about your particular unit.

I have the Boss ME 50. Here's things to try. Use wall outlet to power the 25 instead of batteries. Have volume on amp up, volume on pedal all the way up, volume pedal all the way up(depressed), no gain on amp(use clean channel or clean setting if only 1 channel)effects on amp off(reverb, chorus, delay, boost, etc.) mid range knob below 5. only 1 pickup on, guitar tone knob all the way towards treble. If this puts you in the ballpark you can then make slight tweaks to any of these settings. What we're trying to do is not run a dirty sound from the pedal board into an amp with dirty settings. That double dirt often causes a muddy sound. Aside from that you can back off on various effects in the patches. My 50 has a list of the patches and factory settings, so if the drive, for example is set on 8, I might back it off to 4, or the compressor, or the delay, etc. If you like the sound save it. If not continue on. Start with the amp 1st. Higher output tubes(such as JJ's produce a cleaner sound. Also the demo you heard was not coming from your guitar speaker which may not be on the clean side.

You can restore the settings in the ME-25 (memories, tuner

reference pitch, and knob response method) to the values set when

the unit was shipped from the factory.

Performing a factory reset causes all settings saved in memory to be

lost. If you want to keep the memory settings, use the ME-25 Librarian

(p. 11) to save them on a computer.

1.

Hold down [EXIT] and press the MEMORY DOWN

pedal at the same time.

"FA" appears in the display.

2.

Press [WRITE].

The Tuning Guide flashes.

3.

Press [WRITE] again.

The display flashes and the factory reset is executed.
Never turn off the power while factory reset is in progress.

When you palm mute you create a low frequency pulse which then "rings" in the DSP system of the distortion pedal. It is the nature of the beast. This pulse is to low to be heard directly and is kind of a "step response"... It is like plunking the springs in a reverb tank.

Sell the pedal and get a digitech, or convert it into a looper pedal.