I have an SM025 that, after turned on and set temp. , display jumps erratically well above and also well below set temp. and does not heat correctly. Setting to fully high temp brings heat up, but display still erratic. Problem developed after cleaning and I suspect I may have damaged oven probe, even after being careful to not molest it. Any suggestions? I'd like to be relatively certain before purchasing something that will not remedy my problem. Thank you in advance.