MOTHERBOARD REPAIR USING TEST CARD
Terms of composition:
Main test cards usually have 02 (or 04) 7 Segment LED to display the number from 00 -> FF (hexadecimal). The LED indicates power-5V, +5 V, +12 V, -12, +3.3 V, Reset LED, RUN LED. Communicate with the mainboard with PCI or ISA slot (the card before the main test types only ISA, then the type of PCI, and the two types of ISA and PCI slots). On the card has a main processor chip. Previously the test card is very expensive (~ $ 100 for the types of native Europe, USA, ~ $ 50 for types of native Taiwan, China), so we own tinkering programming processor (they 805x) card test for self-use, cost is not cheap $ 20 chassis. Currently, the price of this test is ill card $ 3 / so many cards you buy a new conditional use test.
Principle of operation:
The Power LED is off the table and enough is enough power LED. Because some source or sources of their cable or power off will not complete (the voltage) for the main -> main not work. If the main run normal LEDs Reset a tip, if the process takes place POST RUN OK, the LED will blink continuously.
Operation principle is very simple. Mainly based on the above process of the BIOS POST (some main card is integrated on the motherboard = 02 LED 7 or 4 / 8 LEDs usually).
When you turn on the device (for AT source) or when you press the button "Power", the first Main + CPU to run, then the process of the BIOS POST operation, it checks the Main + CPU + RAM + HDD + FDD ... generally check each component connected to the motherboard.
This process is going on the screen may show up at all until they hear a beep, then a new screen appears. When you hear a beep (unequivocally) the implementation process is almost complete POST.
If you look further you will see the POST RAM test, HDD, FDD, CD-ROM .. But actually, this is a process or test results alone again.
But when the screen pops up as the main test card "no longer worth taking advantage of" because we can look at the screen to diagnose the errors to fix.
Thus we can see the test card is used only when turned on "power" until the display shows up is OK.
Card Test, the motherboard actually do?
Card Test, the motherboard actually do nothing, if there is little knowledge about the processor, you can do a test card mainboard with similar functions (as we once did, but now that self- Where economics do not make up because in (two sides), purchase of ROM chip, LED, lk .. but the cost was extreme suffering dizzy anymore, save for one school homework is a great processor.)
Why do I dare to claim Test Card Mainboard do nothing.? Nè You see, as I noted above, during POST, if the POST test is a device that will send a code (HEX) through a fixed address, for example, if the CPU test in turn send code from the C1 .. C5, C6 test RAM, send code ... (the code, and address code is sent to only the new BIOS chip maker said the case should not exclude the test card on the mainboard can not use a life of the motherboard) and the test card mainboard only get the value of this task, at this address and the number of technicians up to "Debug".
If the card is the C6 is being tested by the POST RAM (just an example because every life BIOS error codes and addresses are different) then this place forever stand proved problematic RAM. Similarly, if the card is reported C1 .. C5 CPU problem. The code is up, corresponding to the error. This is certainly something in this guide is because you flip the book to see the list and also note the corresponding lookup table is only used for "line" which BIOS. If so, then if you really want to complete the main test that must be present when the examination table of the respective manufacturers bios. This is the internet you can search for more possible by the keyword "HEX POST Code" different "POST code" often show you the lookup table beep (beep diagnostics via PC's BIOS).
So if your test card does not "block" the correct address, or is the error code that you do not know what that code is code is also useless. The China card ($ 3 / Card) only block a fixed address -> be sure you can not test for every kind motherboard. Where the card is not easy to find out anything, or is awkward for some type of motherboard.
If the card is genuine, there would be more "addr switch" to retrieve the address data, suitable for many generations the main test used to test different hardware devices to communicate via computer slot PCI / ISA . People programmable microprocessor / computer interface via PCI / ISA LPT even get this card which is very OK (of course, have to do it or buy the very expensive $ 50-100 depending on the manufacturer).
How to use?
Past articles you've probably imagine how to use, not even use anymore, because it can do nothing?
Well enough is said always to all:
Of course if your mainboard have a problem or problems your PC is a new "hook" test card into a slot on the ISA / PCI space to turn and look. If no picture no sound, no letters, no lights (pan on the source itself and then home above) can of course test card is not plugged into the motherboard so sure. Shutdown plug, if it is to code, and what to do, see if the check encoding, chip manufacturer's BIOS (there are 2 BIOS chip manufacturer is the largest Award and AMI) for main / bios does investigate the corresponding table, no table, then search for the investigation and examination, and then processed. Well.
If you do not want to spend it, I know it would always go up to spend more tired. Where it could help? But I usually use this card and have spent a lot of money to buy a card plugged into the client and then forgot to take the fall off. At $ 30-40 card also is also lost again.
Last words, the card is only suitable for people specializing in hardware and it only helps a little bit since I have turned on "power" to not show up at the screen. This process is very fast, but then ... then it said above. Is only accurate test is only 2-3 small pan as BIOS, CPU, RAM or VGA also other things, the screen was then the error shows up then. In some cases, such as RAM and VGA, the person with little experience has been diagnosed = Beep Code and POST -> only 2 pan, 2 pan in which the pan is also standard.
