Abcon 9v DC 0.4A RH-90040ZZ  Reverse Polarity Power Supply Adapter PLUG

Good working order.

Abcon 9v DC 0.4A RH-90040ZZ
Output: 9v DC 0.4A 400mA 9W
Reverse Polarity (Centre Negative)
Check the polarity of your device.

9V centre negative (Reverse Polarity) 400mA power supply.