ESP8266 Community Forum

Could it be environmental? Electromagnetic interference perhaps, or ambient temperature very high, humidity? Has anything changed around where the boards are located?
If I remember rightly, the wi-fi radio does not switch off unless the sketch specifically tells it to, so even a blank sketch will be doing wi-fi 'stuff' - perhaps the wi-fi around you has changed somehow and it is causing the esp's a problem. Thers are all wild guesses on my part, it's all very odd.

Have you tried powering it with a power bank instead of mains electricity (just trying to rule things out)?

perigalacticon wrote:Thanks but I have tried 3 completely different power sources, 4 different modules, 3 types of module. I previously used all of these for many months with no problem and now this happens! It doesn't matter which IDE I use either. They all fault at exactly the same rime no matter what I do, nothing is affecting them at all! They all run for about 62 seconds then fault. Totally confused. Even a sketch that just prints millis with no libraries included.

But have you taken a voltage measurement at the ESP8266 module 3.3V to module ground? Because Blink should not give you a problems.

The other thing I would try is to restore the module to factory resets. Wipe out all memory and settings.

Miracles do not happen. Somewhere you make a gross mistake, but you do not give us any information about it. Wiring diagram, flashing setting ... etc.
Maybe you used a 4x weak powersource ...