Scale is a common problem for me and my orchids. I get rid of them by spraying a mixture of:
1tbs Neem oil, 1tbs of kitchen dish detergent in a quart of water.
spray in the morning and again 2 days later and again 3 days later. You want to kill the bugs and also get the eggs as they hatch.
You DO NOT have scale if you can't crush the bump with your fingure nail. They are soft and will crush easily.
Dennis