I had a similar problem with my home brewed SMD viewer, described in this thread:
This post is more of a show and tell, rather than a request for help. Getting older and having eyes which don't work as well as they used to when viewing small components close up, something had to be done. Having built a couple of small boards using surface mount components, using a small hand...
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The problem was that the screen would blank when the thermostat in my soldering iron "clicked". The iron is one of the good old Weller TCP types.
One could argue that here are two problems here:
1 The iron is creating emissions which are conducted along the mains, and maybe radiated from the mains wiring.
2 The SMD viewer is susceptible to mains conducted transients, and/or radiated emissions from the mains.
What I did to fix the problem was to take the insides from a component mains filter, similar to this:
I would have liked to simply install the complete filter into the body of the PSU for the iron, but there was not room enough to do that.
So I cut off the mounting flange and input connector from the body of the filter, and just installed the filtering components into the soldering iron PSU.
This has transformed things from having a blank screen every few minutes, to "ooh, it has not done that for a long time!".
I suggest that you try adding a similar filter to your fridge and see what happens.
JimB