Incomplete PC (not working) (Levenshulme M19)

Old but decent quality mATX PC case with motherboard, intel CPU (maybe i5) and 8GB RAM. No power cable or HDD/SSD. No graphics card here but I think there's probably intel graphics on board.

This didn't power up at all last time I tried. I've not tried to diagnose it, but maybe faulty PSU (which is very old) or just disconnected front panel.

Case dimensions 45 cm w, 42 cm deep, 15 cm high.