I have 8 Tenma 72-272072-2720 power supplies and for some reason, one of the supplies powers up in "off" mode, when I press the power switch the CV LED does not light. I can put the supply into "On" mode by pressing and holding the voltage knob for about 3 seconds, I feel a relay energize and the CV LED lights up after that the power supply works OK until I power off the supply and power up later.
I think when I/we were first setting up the supplies we may have pressed the knobs in the "right" way that only Tenma knows that puts the supply into this boot up "off" mode.
I hope someone out there knows the "right" way to press the knobs to restore correct operation. Also, I have the Tenma software working with the supply, maybe there's a command I can send.