First, read all of the information in the FAQ section here about stalling, no start etc. and find the symptom matching your Dad's experience.

I don't have the exact same model as you (mine is 91 740 turbo), so some of this may not apply.
You will hear the faint wine of the fuel pump coming on for a few seconds when you turn the key on to position 2 (not all the way to crank the engine). If you don't hear it, it's not running. Then...

Check the fuel pump relay (large white one) under the ash tray with all of the other relays. You may only be able to diagnose it by replacing it with one known to be working.

Also look under the car (almost directly under the driver's seat) for 2 wires connected well to the fuel pump.

Check for blown fuses related to the fuel pump (#1 on mine).

I you plan on keeping this car and want to try to fix some things yourself, order the wiring manual from Volvo for your model and buy a digital multimeter. You won't be able to do much other than basic maintenence without these.

Good luck.