Nope. I have been using my (InterNachi) testers for many years without a single problem. Only time I need to replace them is after I give one away to a client, or one somehow dissapears from my toolbag.
I would call for a service call from a Microwave appliance tech.
Nick and All, Has anyone reported having two microwave testers burn up back-to-back in the same microwave? Sounds like a bad microwave but I’m not sure what defect would burn up testers. 3-4 seconds each time before burn-up. Thoughts?
some mfr & the fda have specific microwave oven test instructions none include using any nachi beanbag or plastic lighted gizmos
conducting appliance tests by industry recognized instructions may be the best biz model to follow
ymmv