No splash or beeps is a bad sign. Try the generic reset first (short version follows) of removing the power, battery, hold the power button down for 60 seconds, release and re-test.
The nv79 is over 7 yeas old so I would NOT repair. I would pop in a new CMOS battery, as that's under a dollar and worth a try. Repeat the reset again and hope.
As to data retrieval, pull the HDD into the usual under 20 buck USB case if you need to.
The blue light indicating power is on. The red light next to it, circle with a line in it, is flashing slowly. If I press the power button nothing happens. Nothing to see. No sounds. Is there anything I can do to get it working again?