Everytime I had to reboot one of the Dell PowerEdge 1950 we have, there are very long tests and with them the boot sequence becomes incredibly long.
Is there a way to turn off all these tests (or at least speeding them up) ?
If you mean incredibly long as in 2 or 3 minutes before you reach the OS loading, this is normal.
If you mean over 10 minutes before the OS begins to load, there's either a hardware problem, or some diagnostics have been enabled and not disabled again.
What information is coming up on the screen during these 'tests'? Can you reset the BIOS to clear it back to how it should operate?