I actually do want companies to honor their warranty even if I open up the device but generally I do not need to do that if it is under warranty. I was more thinking after that period when it breaks and you can't have the manufacture repair it. These companies still don't want someone doing unauthorised repairs and starting house fires then saying these machines cause fires when really it is was a bad repair. But on the other hand there are countless people that are capable or out of necessity will repair a machine. With my suggestion of registered one time screws it was not to stop the customer from doing work but just to indicate they did work if there was some negative effect afterwards.
On a side note my son accidentally sat on his ereader, a popular model, but there is no place to buy a screen. There were a couple on eBay but they wanted 20$ less then a new ereader. It is frustrating.
Well, but then what would be the consequence of the customer doing work? I mean, either there is some legal consequence to it, then it's a bad idea, or there isn't, then it's useless?! Especially considering that the mere indication that the appliance was opened does not tell you anything about what was done to it and thus whether there is any likely connection to a given defect.
And while you might not need to repair appliances under warranty, mind you that there are other reasons for opening appliances, from curiosity to quality control to wanting to modify things for your needs.
Whether these companies want me to do repairs really seems like a completely irrelevant interest. It's my property, and if property means anything, then their interest to protect their trademark certainly does not trump my interest in having control over my property, or else you could use the same reasoning to justify pretty much any right for them to control and limit what you can do with your property.
On a side note my son accidentally sat on his ereader, a popular model, but there is no place to buy a screen. There were a couple on eBay but they wanted 20$ less then a new ereader. It is frustrating.