Video issues on a Precision 690

Dear All,

I have a dell precision 690 (2007) and issues with my graphics card (Quadro FX550).

The system crashes when booting win7 pro x64. When deleting the drivers and card the system boots and runs video with basic options (have 2 Dell PH2412H monitors). Initial thought was that graphics card is broken. Placing a new card Nvideo Quadro K620 does not work. Sceen does not come on and toggles between signal detection on the monitor.

Here is the worrying part. When booting with the old graphics card the BIOS and SAS tekst on the sceen is destorted. funny characters are seen inbetween the tekst. also when the system is booted into windows small flikkering dots can be seen on both monitors.

Has anyone seen this before? is there a cure and end of life for my beloved workstation?

Kind regards,

Edwin