Hello. I use for several months an LM-2940CT12 to supply 3 PCB's. All datasheet rules were respected.Max current is less than 200 mA. A few weeks ago voltage falls down to 8 V ant head voltage which is normally 13.9 V falls to 10.5 V and so regulation was out of order. I replace the component, and after few days, pb appears one more time. I precise that nothing has been changed on PCB's, and sometimes power works and head and then out voltages returns to correct values. How can we explain that erratic function of reguator IC ?