You don't. There is no such thing as reset back to original factory settings. You need to find the error code and repair what it was telling you in the first place. If you don't know what it is then get someone out to check the whole machine for the reason why it will now not work at all. Error codes are there for a reason. They tell you that something is happening that shouldn't be and you should act on them straight away. If you ignore them then you pay the price.
Mk, August 2012