This is a TEENAGE ENGINEERING OP-1. I purchased a relatively beautiful, late-model unit with a peace sign on the back, used, around July of last year. Since the beginning of this year, I've started experiencing the troubles often rumored to occur with the early OP-1 models, so I'm listing it as a "defective" item. Currently, it works fine most of the time, but when it's not working well, it might not turn on with the first press of the power button, or the power might turn off if you lightly touch near the power switch during startup. After a few attempts to turn it on, it will work without any issues once it stabilizes. https://note.com/alloutofsync/n/ne590d6be991e Therefore, I haven't experienced a situation where I couldn't use it because it wouldn't turn on. There are no problems with connecting to a computer, other operations, buttons, or knobs. You might feel more secure if you consider getting it repaired. (There's an article about fixing it by opening the back cover and doing some work, but I haven't tried it because I'm not confident.) Includes the dedicated USB cable, box, and Decksaver. Please consider purchasing it.