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How do I use this device?

  • Designed to troubleshoot PC boot failures, when PC doesn't even show Video Card/BIOS screen (thus no error code/info is available)
  • 4-digit numeric display for detailed diagnostic code
  • With USB interface
  • Plug-and-play
  • Comes with power cable & Chinese manual
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Looks like the first step will be to learn Chinese in order to read the manual... – Mokubai Jul 23 '11 at 9:07
There is really not much to using them. You just plug them in and the look up the code that is displayed in a table that explains the meaning of the code. The codes used are not some "universal error code" and may differ by manufacturer. But, "Plug-and-Play" is, of course, a Windows function. It implies to me that it needs drivers and Windows. But it could simply be a mistake in denotation by a translator. – Abraxas Jul 23 '11 at 9:55
up vote 3 down vote accepted

Many motherboards put one or more progress/status codes in a specific memory locations while they are running their diagnotics and these devices read those values and display them. The idea is that on a faulty unit that can't even get as far as driving a display you can use the supplied information (and sometimes the data supplied by the motherboard or computer manufacturer) to get an indication of which component has failed.

Under most circumstances, these failure codes refer to individual chips or sub-components (eg: keyboard controller failure or stuck interrupt line x) and so although you can perhaps see why a board has failed you are not likely to be able to fix the fault without some specialist board repairing and reworking tools.

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It only shows onboard failed components? Not video card, processor, memory etc.? – Boris_yo Jul 24 '11 at 20:56
Only the results of the onboard tests - you may get some indication of faults in certain areas you mention but only for the interfaces to those bits - for example, memory controller error or stuck address line - but no in-depth testing of CPU or RAM. – Linker3000 Jul 25 '11 at 20:59

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