美国采购需求：电子、照明

I recently purchased two units of your product, and I'm experiencing an issue with one of them. While one unit functions perfectly, the other fails to respond to the switch. Even when I set it to “ON,” it remains on continuously and does not turn off as expected. This inconsistent performance is concerning, and I need to determine the right course of action. Could you please advise on what steps I should take next? Is there a troubleshooting guide available, or do I need to arrange for a replacement? Your prompt response would be greatly appreciated, as I rely on these products for my needs.