Bios flash killed my graphics card?

Hi, i've tried to flash my old Radeon 9550 in attempt to tune her a little bit up.
I've proceeded according to this tutorial: http://www.techpowerup.com/article [...] idcard/107
In DOS mode i've got the confirmation, that the flash was successful but since then my PC isn't booting anymore, at least not with the flashed card, I had to replace it with an GF.
There's no way to restore the old BIOS, right?

You can use an old pci VGA, an onboard motherboard Vga or you can try doing it just using the keyboard and checking what you type

I own(ed) a Radeon 9550 and tried to flash it with a 9600 bios, since the 9550 is a cut down 9600. I do have a backup of the original bios but the PC isn't even booting when the graphics-card is installed inside the AGP-Port.
I've tried the card at another PC and screen stays black as well and is beeping.
The card is probably f***ed.

Well, as soon as I insert the card into the AGP-slot the PC refuses to boot, this two LEDs beneath the power button turn red/orange instead of green. When I remove the card and use an GeForce he works just fine. If I could gain access to the card via PCI-mode I would give it a try but my HP bios has this option not available.
I could try to fix this by flashing the MB-bios too but I doubt it would unlock such featueres, besides Idon't want to wreck my MB-Bios as well.