Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
The first camera's problem might be owing to stuck buttons or stuck keys.
Normally I would recommend using a contact cleaner, but on a sensitive and fine-scale-design device with sensitive optical components, use of such sprays is highly unlikely to have good outcomes, since it can contaiminate other elements of the device, especially the sensitive optics.
The second camera's problem is quite obviously a case of decayed circuitry, with a heat-sensitivity element that makes the malfunction mainly or only occur once the circuits have warmed up.
In both cases, sending to Sony for repair is advisable. This page is where you may initiate a repair request:
If you wish to take the cameras to a Sony Service Center near you, instead, one may be located through this page: