DevTerm CM3 OS not booting?

I created an image of DevTerm OS CM3 image on a brand new SanDisk SD Card using “Win32 Disk Imager” under Windows 10. It was pretty easy. I inserted the micro SD into the unit, power up and it does not do anything. There is no beep (I read that it should beep), or noise, or nothing is displayed on the screen. The batteries are brand new and fully charged. I charged them with an external AC charger.What do you think I am doing wrong? Thank you in advance.

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I don’t think it should beep - at least my DevTerm never beeped during boot.

Are you sure the image was completely written to the SD card without errors?

Is the power LED glowing? I noticed that I have to press the power switch for about a full second to have it switch on.

Can you hook up an external monitor through the micro HDMI?


Hi Julian, sorry for my late response. I read in another posting that it normally beeps but I take your word for it that it is not supposed to. Yes, I have pressed the button for at least a second. Your suggestion to connecting it to an external monitor is very good. I’ll give it a try tomorrow. Thank you.


Try Balena Etcher instead, it is rock solid for writing Raspberry Pi compatible images.

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Than you so much for your input. Up and working now.