faulty power button that flashes amber and refuses to turn on system could be suspicious sign of system power supply failing.  For now you can plug the power cord into a power strip w a switch. Instead of unplugging the cord use the switch to turn off/on power and see how long it works in this way. If psu is good, it should work indefinitely, but if psu is failing, there will be a day in the near future your pc would not turn on no matter what.
I never had issues with my optiplex 3060 micro, but it's few days since the power on button led blinks orange and it doesn't turn on. It blinks 2 times, then there's a pause, then it blinks 1 time. I've searched and this should be linked to "bad motherboard" in other models. The point is that I solved by unplugging the power cable, plugging it again and pressing the power on button.. then it boots normally. When I turn it off, this repeats, so I'm unplugging my power cable each time to get it working. Any advice? NOTE: I run my "dell command | update" but looks like my system is already up to date, even if it keeps saying that I did my last check & update on December 2019, while I have run scans on March and April too
optiplex 3060m amber light