In late 2019 some friends and I (all with an engineering background) started a local repair initiative. The idea was born soon after I fixed that sailboard electric system and two of my friends where with me on that trip while I chatted about repairing my fully automated coffee-machine. It took a few turns until we could begin: find a room, clarify some legal issues and so on. And then the name: for legal/license reasons we could not call it a repair café as this is a registered name. But once all those details were cleared we announced a monthly voluntary service in the local newspaper.
We had some 3 or 4 very successful sessions to which local citizens brought their broken ironing-board, toaster, coffee-machine, vacuum cleaner, hifi system, transistor radio, travel alarm, kitchen machine and what not. Some of it we were able to fix, others was broken so that repairing was not possible anymore and a few things were just designed to not support a repair job. Then the corona pandemic stopped us.
After a couple of months have passed by in 2020, we opened again in the autumn for another two sessions before the next lock-down hit us again. We are since then closed and by just talking to people we meet at the local supermarket etc., we could easily fill a list of stuff that has to be taken care of. Currently, we are planning the ads for the next sessions since the number around the Corona virus are looking promising.
Nevertheless, I needed some exercise and since our ceran oven showed a problem with the front left cook-top, I thought I give it a try. From the symptoms it was unclear what the cause could be, because it was one of those intermittent failures which sometimes show up and sometimes everything is just working fine. The affected cook-top has two zones, where the inner zone is always used and the outer one can be added if one is cooking in a larger pot or pan. Adding the outer zone is controlled by a hall sensor underneath the glass plate. When turning on the cook-top and adding the outer zone it got lit up immediately and things seem to work just fine. But after a while, only the inner zone is working while the outer one stays off. But it could come back to work after a while. Cooking was just terrible on this cook-top in a larger pan.
At first, I watched a few videos I found on youtube to get an idea how things are setup and what I need to take them apart. Of course, the reality is a bit different as we are talking about 20+ year old equipment. But it was enough to get some ideas.
I had the feeling that the cause of the problem is a dry soldered joint at the hall sensor because that is located close to that outer zone of the affected cook-top. Once I had disassembled the whole thing, I did not find anything suspicious. Both sensor units looked fine.
Since I did not know any better, I simply exchanged the two units, put the parts back together and we are happily cooking ever since.