You can try something like this https://www.amazon.com/SoulBay-Universal-Switching-Selectable-Electronics/dp/B01N7RS0NG
The downvote fairy of sanantonio has visited, I see.
OP, do you have a photo of the jack into which the power adapter plugs? It's probably a plain 2.1mm or 2.5mm barrel plug. The polarity is almost surely with negative on the outside, as denoted by this little diagram probably molded into the plastic:
⊖ —( •— ⊕
The only thing left is the voltage, which is probably somewhere around 7 to 12V. However, since there are so many variables, one of these will help. Just slowly increase the volts from the minimum until the thing works as expected.
https://www.amazon.com/SoulBay-Universal-Switching-Selectable-Electronics/dp/B01N7RS0NG
This worked good for me. https://www.amazon.com/dp/B01N7RS0NG/ref=cm_sw_r_cp_apa_fabc_ciqQFbEA0NT21?_encoding=UTF8&psc=1