There is 3 adjustment pots on the inside. 1 controls the amp meter, 1 controls the volt meter and the other one controls the crowbar adjustment.. Neither control the voltage, that is done with the knob on the front..Take the cover off and look for any adjustment pots. There's nothing else in a linear power supply to adjust except for the voltage output. Connect a voltmeter to the output and turn the pot and see if the voltage changes. Pretty simple
mine will only do about 40-45 amps before its starts clicking on and off.
LC
It seems that the voltage knob will not crank it up to 15 amps...