HP printers will automatically upgrade the firmware to the latest version if users do not disable related functions, which may block compatible chips. To solve this problem, we can downgrade the firmware to the previous version. 下面我们将以惠普M454nw打印机为例,给大家展示固件版本的降级方法:(温馨提示:给打印机固件降级的过程中,请确保电脑处于正常开机状态并且已连