Then it's likely more than your router got fried. We can be pretty sure that you need new RAM. If only one of the sticks work in slot A1, then you need to buy a new set. A new set will at least enable you to see if the slots on the MoBo are bad as well. At the same time, if you are having voltage regulation issues, it could damage both the new RAM and other components connected to the MoBo. You have a few options here;
1. Buy a new set of RAM that is compatible with your MoBo and we can guide you through some steps that may help identify any other issues.
2. Bring your PC to a local repair shop to have the components individually tested.
No matter what you do, at this point, you need to get a Hard Drive that was not affected by this lightning storm and backup all of your data and important files to it just in case the Hard Drives installed were affected by the surge and decide to die as well.
After this is all said and done, you need to invest in quality surge protection. I live in Florida, the lightning capital of the world. I have had a whole house full of electronics rendered overpriced paper weights due to lack of proper surge protection. I recommend a direct feed surge protector, which can be installed by your utilities provider at you Breaker Panel. Also, you should have surge protection on your components individually. Pay attention to how many outlets on your surge protector actually protect against surges. Your cable and phone lines that are connected to electronics, such as your router, cable box, t.v. etc, should also have protection.