Monitor working but not recognized by MB

My comp is approx. 3 years old and worked well until sometime last year. The most recent thing that happened is that the screen stays black during boot up. For quite awhile, if you would just keep restarting the computer, it would eventually connect with the monitor and then you could see the desktop and use the computer. Whether it booted up or not was clear from how long the shut-down required. If the computer shut down immediately, it probably didn't complete boot-up, usually because of damage to the OS which then had to be fixed. If it did boot up, the comp didn't shut down immediately when you push the button.

The bios has continued to work throughout. The graphics card, monitors and cables were all tried on another computer. I switched out the PSU and that didn't make any difference.

Questions: Is it probable that it's a problem in the MB somewhere? And if so, how would I go about finding a MB that would still be compatible with my existing chip?

The board is an Infinity NF UltraII-M2 and the chip is AMD Athlon 64 2X.

 

I got a new MB and tried to take the chip out of the old MB, but discovered that the chip is glued to the heat sink. Is that normal?

 

Just to get back to you.
I took the chip + heatsink to the store and they said this getting stuck like that happens. They took a pointed object (screwdriver maybe?) and pried it apart. The paste was dry.