Power surges and power supplies

I've got a question for people with real electronics expertise, which I don't have. I've got a laptop that without any apparent cause has stopped starting up. The owner of the laptop says there were lightning storms between the time the computer last started normally and when it was found to be not working. The symptoms, lack of other apparent causes upon further inspection, and the storms at the time kind of suggest a lightning strike could have hit some components in the laptop.

However, the power supply was the only cable connected to the computer for lightning to travel to it over and I've run some tests on it. Checking it with a multimeter you find it is outputting close to the right voltage (18.9 volts instead of 19), and when plugged into the laptop, it is powering some of the peripherals on successfully like the DVD drive, hard drive, etc. The power supply seems just fine. Need the power supply fail tests like the above if it has taken a lightning surge that reached the computer through it, or could it still be working after having let lightning through to damage the computer?

Expert responses are appreciated.

Thanks