When the MicroTech's batteries are too weak to properly power the unit, the MicroTech briefly resets itself (similar to quickly switching the power off and back on) over and over again.
This reset sometimes happens when the user presses the Mode button to enter a diagnostic function that places a heavy load on the batteries. In this case, the reset occurs while the user is still pressing the Mode button.
The MicroTech has a "feature" that displays its firmware revision when the unit is turned on while the user presses the Mode button.
When dead batteries cause the unit to reset when pressing Mode, the user will notice the MicroTech "flashing" the firmware version number.
A replacement of the batteries or attaching the AC Adaptor should solve this problem.