It really doesn't matter about the make, spec's and the OS:
1) because a blackout will do the same damage to any computer regardless;
2) you computer is 'trash' now (LOL).
Here are a few links of interest to you:
Power Surge Facts
Quote='Fact: Over 40 percent of all computer crashes and data losses are caused by power surges'.
Protecting your Computer
Quote='PCs house voltage-sensitive components that a power surge can easily damage. A spike in the electrical output from a wall plug will at minimum shorten the life of your computer. It could also crash and destroy your system, taking all your data with it'.
Quote='Your entertainment system, television, VCR, CD player and stereo system are valuable items and need to be protected accordingly. Using a surge protector is one inexpensive way to protect this equipment from power fluctuations'.
Also there is a ton of info on 'Google' with the search terms 'power surges and computer crashes'.
I seriously think you need to get a new computer. Since you are not that familiar with computer mechanics I would suggest bringing it into a reliable 'computer professional'.
The monitor and the mouse are working etc so it is in the main body. Trial and error could work, ie replacing a component with another to see if it helps. It could be various components.