POST Card Error Codes?

I just purchased a POST Card that you plug into the ISA or PCI slot on your motherboard to test for error codes or whether the board is good or not. Anyway, does anyone know where I can find a complete list of the error codes? One of the boards I tested came up with two different error codes which aren't listed in the code book that came with the card. At first, the error code "FF" comes up and stays on that code until I push the reset button, then it changes to "db". I don't receive any beeps or any other codes after that. Everything seems to be running (fans, lights, cd drives, HD, etc.), but I get nothing on the monitor (which was the reason for buying the POST Card!). Any help would be appreciated! Thanks!

 

Well look here for POST codes: http://www.bioscentral.com/postcodes/attbios.htm

But from what you have described a duff graphics card would seem favourite. Take the card out the boot and see if you get POST beeps or anything else on your POST card (and I always thought that was something you sent whilst on holiday!! )