Percussive maintenance refers the use of physical concussion, a knock or a tap, in an attempt to make a malfunctioning device work instead of asking for professional help.

“敲打式维护”指设备有故障的时候，不找专门的维护人员，而是用敲打的方式让其恢复运转。

Percussive maintenance happens when your piece of electronic device — television, computer, etc — won't work, you give it a sharp unscientific whack to revive it. And it often works.

电视或电脑等电子设备出故障的时候，你有时会通过敲打的方式让其恢复运转。而且这种方式通常都会管用。

For example:

My computer keyboard didn't work yesterday, I couldn't type even a single letter. After a percussive maintenance, it worked like a newly-bought.

昨天我的电脑键盘坏了，连一个字母都打不出来。我给敲打了一下，然后就跟新买的一样好用了。