You may want to review this Apple TN: Apple Portables: Troubleshooting MagSafe adapters
Without dissecting a working unit to document the components and trace-out the empty PCB to make your own schematic on how the unit is wired is the only way I know of to reverse engineer it.
As to the root issue you stated you think a power surge damaged the unit. Lightening can also kill a plugged in adapter.
I would start with getting a good surge suppressor to plug in your power adapter. But it will be of little benefit if you don't have a good building ground and have a correctly wired grounded outlet to plug it into. Here is were you'll need to find someone with the needed skills to make sure the fuse/breaker panel is wired correctly.