First of all, let's look at the power button issue. The power button should *always* work for power on and power off. Let's do some diagnosis. Can you remove the NUC's motherboard from the chassis? If you can, hook it up without the chassis, plug in power and then try powering on by pressing the power button on the top surface of the board (see Item D in Figure 1 on page 14 of the TPS for where this button is located; you can download the TPS with this link: D54250WYB/D34010WYB TPS). Now, the power button on the chassis is just an extension of the power button on the board. When you press down on the chassis power button, it simply presses down on the board power button below it. Thus, if you can power on and power off consistently with the board's button, the issue is that the chassis power button is not properly pressing the board power button below if when it is pressed. When you return the board to the chassis, you should be able to adjust the board's position so that the chassis power button properly presses the board power button.
If the board power button is not working consistently, your only choice may be to add an external power button yourself. On the bottom surface of the board, there is a header that allows you to hook up an external power button (and also a reset button, a power LED and a disk access LED if you want those as well). This header is shown as Item H in Figure 2 on page 16 of the TPS. You will need a cable with 2mm pin pitch or a 2mm to 2.54mm pitch 2x5 pin conversion cable to use a standard front panel assembly.
Hope this helps,
Amazing I didn't know there was a power button on the board.
Opened up the nuc, took out the mother board, it does power up when i hit the button. however I get a soild green, and flashing blue then it powers off. Progress.
Going to look up what those status lights mean. (hopefully it's in the pdf you sent)
You're help was great, thank you Scott Pearson.
blue was no memory (because I took it out)
So turns out the button on the top i guess wasn't making proper contact with the button on the board. (doesn't explain why it was turning it off though) but long story short, I took it apart as you said, (cleaned out dust and unplugged the cmos battery) and it works flawlessly.
So again thank you Scott Pearson, you were great