Thanks for the reply PottedMeat. So can these things fail with normal use or should I look into what what may have caused it? It was plugged into a surge protector and everything else on it is running fine.
Also, is it worth buying a new, small power adapter?
First, a larger adaptor is not a transformer with diodes. If it was, then excessive voltages would be inside the router. A large supply is an older technology switching power supply. Smaller one is the new technologies due to higher radio wave frequencies, smaller inductors, and less energy dissipation.
Routers typically have a single chip power supply inside to convert unregulated 12 volts to maybe 5 volts. If true, then any adaptor with the same poor, regulated voltage and sufficient current will work fine.
A power strip protector may have made damage easier. View its numeric specs. It does not claim to protect from types of surges that typically cause damage. Damage was because you permitted energy to enter the building. A lightning strike way down the street was a direct strike to every household appliance.
Which appliances were damage? To have damage means a current incoming and a current outgoing. All appliances had the incoming current. But a better path to earth is often via appliances connected to other already surge protected wires. All phone lines and cable are required by code to have superior (earthed) surge protection. To obtain earth ground, the surge found an easiest path - via that router. A protector adjacent to appliances makes the hunt for earth ground easier.
Why are some appliances damaged and others not? Which appliance gave that surge the better path to earth? Damage because you permitted that energy inside - to go hunting for earth destructively via some appliance.
Your long term solution is what you do not have and have probably never heard about. One 'whole house' protector has been the effective solution for over 100 years. But it does not have obscene profit margins found on power strip protectors. So you heard of the ineffective protector. Advertising never taught you what was always installed when damage can never happen.
More responsible companies provide the 'whole house' protector: Siemens, Square D, Leviton, General Electric, ABB, and Intermatic are but a few. A Cutler-Hammer solution sells in Lowes and Home Depot for less than $50.
Protection means energy earthed before entering a building. You do not have that. Your router was a 'canary in the coalmine'. You have near zero protection. Power strip protector did exactly what it claims to do - effectively nothing. Informed homeowners earth one 'whole house' protector. And upgrade the only thing that actually does surge protection - earth ground.
Will any supply work? Open the router. Does it use an industry standard single chip power supply? Then any DC voltage from 8 volts to 14 volts will work fine for that Netgear router.
