What the charger must offer

Asking is not getting

The chip sends a request. The charger answers it, and it can only answer with something it was built to produce.

A refusal is not an error condition. The supply simply does not accept the request and carries on doing what it was already doing, which is 5 V. Nothing on the board changes: the LED is lit either way, nothing gets warm, nothing clicks. The only place the difference shows up is on a meter at the screw terminal.

That silence is the single biggest source of confusion with these boards, and it is worth internalising before you start blaming solder joints.

Read the case, not the wattage

The voltages are printed on every compliant charger, usually in a line of small type on the body:

Output: 5V⎓3A  9V⎓3A  12V⎓3A  15V⎓3A  20V⎓3.25A  (65W Max)

That list is the contract. If 15 V is not in it, no trigger board of any design will produce 15 V from that charger, because there is no 15 V in there to produce.

Wattage is a separate number and it does not imply the list. Plenty of 30 W chargers do all five voltages; plenty of 45 W chargers skip 15 V. And the wattage is a ceiling across all of them, not a guarantee at each one — a 30 W charger at 20 V is offering 1.5 A, not 1.5 A and 30 W of headroom.

The current falls as the voltage rises

Watts are volts times amps, so the same charger offers less current the higher you go. A 65 W supply is good for 13 A at 5 V on paper and about 3.25 A at 20 V — and in practice the 5 V figure is capped far lower by the cable and by the specification.

Pick the voltage your load actually wants rather than the highest the charger will do. Running a 12 V strip from 20 V through a regulator wastes the difference as heat, and the strip does not care where the volts came from.