Picade starts with a hiss, then Picade board LED pulses as does Button bar then repeats

Using an official Pi power supply. Double checked wiring. All seems fine.

After 3 seconds or so Picade board LED lights up, speakers emit hiss and a whoosh sound. Button board LED goes from red to green then repeats. White flash on screen. The whole cycle repeats. Nothing else happens.

Pi booting up OK.

Any help appreciated.

I can’t really relate to your reports in term of hardware description… what board are you using, can you post a picture?

Resolved issue. I was using a dual SD card shim which it seemed the Picade board hated. Switched on one SD card all fine. Although currently have no sound. Working on that.

OK, let us know if you get stuck with sound, although I still can’t relate to your report…

The Picade ships as either an external PCB that you connect to the USB port or a HAT form-factor add-on that you pop onto the Pi header… neither have activity LEDs as you describe, nor do they take/care about SD. So you need to tell us more about what you are using for us to be able to help finding the root cause of your issue(s).