See my other replies above, but I had to take on debt to even get the hardware made, which then required me to get a full time job to pay off the debt. I tried to continue running the business on weekends but after years of burnout, working 7 days a week was killing me. I simply exceeded my capacity to continue operating the business, and so was unable to try selling the boards to refund people. I elaborate on this in the other replies but basically I had pushed through burnout for years on end by that point, and eventually you just hit a wall. You get to a point where there’s nothing you can do but walk away. That was 5 years in with no hope of success. I felt awful for letting all those people down, but I simply couldn’t continue to operate the business in any capacity, and no one wants to buy a failed business with loads of debt that has been eclipsed by venture funded startups shipping successful products.