This is what i found. https://www.amazon.com/dp/B07F2KSY9Q/ref=cm_sw_r_apa_i_YGhSEbKBE1XZY

To be honest the device won't pull more than the rated amps unless something is seriously wrong with it. It may run around 75% of the rated amps. Same goes for the voltage, it should run with a certain amount of tolerance so 19v-21v should work, each manufacturer has its own way but typically they leave a bit of room in the psu just incase, also note that with a bit lower voltage you may pull a little higher amps. One thing to note is why the old supply died. Is there something wrong with the device[dock], was there something wrong with the psu, house voltage problem or is it possible it died from age. You may want to find these things out. Also please do not go buying many different power supplies and trying them as this may damage your device, so do some research first as i am not responsible for any damages caused.