PCI card not detected


We manufacturer a PCI card as part of our product. Recently we have had a
number returned by customers as faulty.

On investigation I find that what actually happens is that the faulty
cards are not detected by Windows. ie ‘devcon hwids *’ does not list the
card. Just as if the card where not plugged into the PCI slot. Doing a
‘devcon rescan’ does not change the situation.

But I have also found that if I put one of the ‘faulty’ cards in a
different PCI slot then it is detected and goes on to work correctly -
indicating that the card is not undetectable.

My questions are:

1: Are there any circumstances when the system (pnp manager, BIOS or
whatever) will ignore a device.

2: Is there a way to force the system to rescan for devices - at a lower
level than ‘devcon rescan’ which does not help.


Phil McHugh
Newspaper Software Solutions
Agfa Graphics

Tel: +44 (0) 1525 850649
Mob: +44 (0) 7836 364655


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This is a problem in your hardware or PCI core logic. No, this is not a problem in Windows,
unless no other PCI card works in this slot.
You can quickly test by booting a Linux “live CD” and lspci, Linux most probably will see same as Windows.

PCI slots have slightly different electrical/timing properties, it depends on their distance from the root chip and so on. Right now I have one such FPGA proto board from a known vendor that behaves exactly like you’ve described.


>1: Are there any circumstances when the system (pnp manager, BIOS or whatever) will ignore a >device.
This could be happened if your device breaks PCI protocol. Try to use PCI bus analyzer to see if the device works correctly.

Igor Sharovar