no light on dashboard/ignition

[ayookeleye]

Pls help me,

I've a Laguna 2004 1.8 16V model, the battery was flat so I used another car battery to start, initially I made a mistake in connect the jumper cable, immediately there was a spark I correct the mistake, start the car allow it run for a while then went out got to where I was going without any problem, parked the car, locked up, only to come to the car about 5hours later, insert the card nto the reader, the reader did not read the card and there was no error message display.
So the car could not start because there seems to be no connection between the car and the card. I immediately went for the second card the same thing happen, change the car battery, change the battery terminals, but the situation remains the same.
Presently, I can't start the car
Thank you