My Husband's computer tower will not turn on, no electrical problems can be found, could this be the cause?

Yes it is possible, and highly probable. But it can also be a coincidence. Depending on the age of the computer, the power supply can be failing or a power connection on the motherboard can be loose.

If the computer does not turn on at ALL (no power) then it is not a virus. A virus is a piece of malicious software that cannot alter the hardware in such a way that the computer wouldn't get power. There may be some that can cause the computer not to boot properly and seize at certain points in the process, but none that will stop all power from entering the computer.

That being said, having large numbers of viruses or other malware loaded onto the computer could have overloaded parts of the computer. More viruses/spyware/adware/etc will cause the computer to run harder causing more wear and tear, eventually resulting in the computer breaking down faster than usual, much like flooring the gas pedal constantly in a car.

In all likeliness, either it was just that time for the computer to start having problems, or the malware was the problem. My recommendation would be to have the power supply and motherboard checked out first, assuming the computer truly is getting no power.

Unplug it and wait for the caps to discharge. Plug it back in and try it. This sometimes works if your power supply is going bad.