A post card is a diagnostic board with a digital panel. The error codes of the motherboard are displayed on the indicators, thanks to which the specialist can determine in which node of the personal computer the malfunction is located. Depending on the type of BIOS chip, the codes may vary. If no faults are detected during the diagnostic process, the Post-card displays the message "FF" on the indicator (it may differ, depending on the type of BIOS). This value remains unchanged in the course of further work of the personal computer.
Post cards come in many varieties. For example, the Post CodeDual card has a double-sided display, which significantly increases the convenience of reading information. All types of devices have LED indicators that indicate the presence of voltages +3.3, +5, -12, +12 volts in the computer, as well as a Reset signal LED. The post-card for connecting has different slots - PCI, ISA, LPT, miniPC and others.
Let's see if these devices are really necessary, in what specific cases they can be useful. Very often during the assembly of a new computer, emergency situations arise. So, for example, by turning it on, you find a black screen with no signs of life. In such cases, you have to pull all the connectors, rearrange the jumpers on the motherboard, and so on and so forth. Engineers of service centers also have a hard time in case of operational trips, when it is necessary to quickly find out and eliminate the cause of the malfunction. Very often, the latter have to take the system unit with them to troubleshoot the workshop.
So for anyone involved in the repair or assembly of computer equipment, a Post-card will be an indispensable assistant, especially since the price of this device is low. Ordinary users of personal computers can also purchase such a device, because our people always try to fix any malfunction on their own and only in extreme cases resort to the help of specialists. Thanks to the poke method, most computer malfunctions are eliminated. But this method is good if you have several similar system units at hand. In this case, you can take the boards from the working unit and replace each one with the faulty one until the latter works. However
if you don’t have spare parts, then the search begins on friends, or on the advice of familiar “specialists” you have to buy certain blocks. Thus, a post-card would help to avoid unnecessary expenses, because computer components cost quite decent money, and finding and buying the latter takes a lot of time.
Post-cards are easy to use, everyone can figure out how to use them independently. These devices do not require a monitor for their work, they allow you to test a personal computer at an early stage when sound diagnostics are unavailable, and visual indication is much more convenient than the need to calculate the number and duration of computer beeps. A post card also allows for the diagnosis of peripheral systems.