So, my sister (she lives in Spain) tells me that last night there was an storm and the electrical system up and downs did crash her iMac 400 (I gave her as a present) and now it fails when loading the system.
Basically, the system is loaded but once desktop, icons, etc are set, the computer mouse, externals, etc do not work. It sounds like an extension problem to me (I told her about starting up the system with the "shift" key to check if the start up without extension works and later open the first aid disk utility to verify and check the system.
Any additional ideas?
I hope is not hardware related.