Technically I imagine it is not the graphics card per day that loops, but I have an old Nvidia Riva TNT2 M64 PCI which I previously had installed in my Digital Venturis 575 but then wanted to use in my Compaq DeskPro 590 instead.

My memory is a bit wonky, but I do believe I have booted to the Compaq Computer Setup before on the card a few weeks ago but I may be mistaken and it was on my GeForce 4.

Now today when I tried to start up the computer it shows the graphics unit details correct then black screen as always - and go back to graphics details. And thus it continues with. If I remove the TNT2 and use the onboard graphics it continues to RAM counting.
So the computer won't boot with this graphics card. The Venturis 575 had no issue continuing, and the Compaq also usually booted fine with the GF4.

Anyone expirenced a similar mystery?