Can I use 24V2A power adapter for Zhongjing 4700 scanner? I have a 24V2A power adapter, which is used when plugging in, and now the computer is unresponsive.

The parameters of the external power supply of the MICRO 4700 scanner are "DC, 15V, 1.25A", in which DC refers to the stable direct current rectified by the mains voltage; 15V means that the rated working voltage is 15V, and the deviation of 10% is usually allowed, for example, it can work normally and continuously within the range of 13.5- 16.5V; 1.25A is an external power supply with an indicator light, which can provide a current of 1.25A at a voltage of 15V. Your power supply can provide 2 amps, which is certainly enough.

So the problem is that your power output voltage is too high, exceeding 60%. I think the scanner or the power supply is burnt out.

You should first check whether the power supply outputs a nominal voltage of 24 volts with a multimeter or a DC voltmeter. If so, the scanner is broken. If there is no voltage output, find a power supply that meets the requirements and connect it to the scanner to see if there is any response. Of course, if you know electronics, you can also use a multimeter to measure the power interface of the scanner.