Ring outdoor siren LED

Hi, I have the new outdoor siren and I’m just about to put it up. I have tried to test the led light up of the ring logo. In a dark to pitch dark room it doesn’t light up. I’ve checked all the settings and it’s turned on, I am using with a battery pack and the d batteries but it should still work.Any ideas on what might be wrong, not keen on putting it up on the wall until I see it lighting up. The red led’s work on the test. Thank you