The 3B card dispenser consists of five main parts: card reader, control card, data cable, data interface, and power interface. The control card is inserted into the ISA slot provided by the computer motherboard, and the power supply shares the computer power supply. A properly installed card dispenser has several significant features: ① When the computer host is turned on, the card dispenser indicator light flashes once and then goes out. ② When reading the card, the indicator light of the card issuer flashes once and then goes out Information reacts quickly when reading cards. Therefore, when the card dispenser has the above three characteristics, it proves that the card dispenser has been installed well and is working properly. Another thing to note is the installation direction of the card reader on the computer. Generally, the indicator light is located on the left side of the panel.

Improper installation of the card dispenser is mainly manifested by the indicator light being constantly on or not turning off, or the system prompting "hardware detection failure", "system communication error" and other messages, or the computer crashing when inserting the card. If the above phenomenon occurs in the card dispenser, the installation of the card dispenser should be adjusted in a timely manner. Firstly, check if the power supply is outputting normally or connected properly. Secondly, check if the data cable is connected properly. Lastly, check if the control card is securely plugged in. If the slot is too loose or the position is offset, it is recommended to try inserting the control card into a different slot. It should be emphasized here that there is a situation that is very noteworthy. When the control card is not fixed properly or not in the correct position, the indicator light of the card dispenser sometimes stays on, sometimes it is normal, and the card writing is also normal, but it often causes the card to be damaged or the meter to not recognize the card. Therefore, it is very important to install the card dispenser correctly.