There is a real good reason why you don't see service like that anymore. Its because that kind of service does not win all of the customers for the business like it needs to. He gave away his time and knowledge, in the losing effort of hoping you will make all of the hardware purchases that you need at his store, and of course at his prices which are usually higher for the most part than you will find the same items for at a place like Lowes, or another big box hardware store. While you can say you will now buy everything from him, all you need to do is look at just how many people are going to the other stores to see just how much his service really means to the public at large. By him not charging for what he did, you got to have HIS cake, and you got to eat it too. Someday all too soon you will see his business close and you will be left to wonder why that happened, cause he was such a good guy. Running an honest business does not equal "free to me", in fact now when he finds himself in a situation where he has to charge for his time and the expectation has been set that he usually did something for free, he will now come across as looking as anything but honest in his business. This should all sound real familiar, because its one of the biggest problems we face in this trade. While guys try and do something free once in a while to help build their businesses, they teach their customers that their time is worth less than it really is. They create an atmosphere where the commodity ( something like a tire ) is the important part of the transaction, not the training and the skill that is required to replace it safely and correctly. Meanwhile, by giving up an important revenue source they turn around one day and find that they cannot afford the tools and the schools their people require to stay up to date with the technology that is hitting the streets today.

I have a similar issue but didn't manage to solve yet. When I open the induction cooktop, I get displayed the letter "L" and from the instruction manual, this means that it's looked. I followed the instruction to unlock it but was not working, I got the following errors, different for each eye. From the instruction manual, it should be "0" to get unlocked by another click on the unblock key. The issue looks not to be on the sensor for the unlock button but somewhere else. Any idea what can be? This happened suddenly, yesterday night everything was ok and working and in the morning I got into this problem. The induction cooktop had no intervention and was working fine until this issue for many years. Any ideas of how this can be solved because it's hard now with the covid-19 to call someone from service and come to have a look?

I had a problem like that once with a similar design door. I finally figured out that the problem was not with the lock. It is possible that the door has warped slightly and is putting pressure on the top or bottom lock/pin, which causes friction and can make it seem like the lock is stuck. If it's a door that opens to the outside, it's also possible that the pin at the bottom has gotten corroded a little from moisture. Stand on the side the door opens to; then use your shoulder to put some weight against the door toward the top, or your foot to provide pressure against the bottom, and see if you can get the handle to turn.

I doubt that a loose thumb turn is evidence of tampering, I'd be more inclined to think it's just come loose. These kinds of things are often just press fitted together unless you see something like a screw head. Contact Marvin or your dealer about replacement options.