I have a set of Presonus Eris 4.5BT speakers that were working perfectly for a few months. After plugging in a pair of headphones (Sennheiser HD25) into the 'phones' socket for the first time then removing them (and no other change in the setup), I now have no audio out from the 4.5BT main drivers, but still have audio via the phones jack if I plug my headphones back in.
The fact that I see audio from the headphone jack and see the 4.5BTs power light come on presumes the signal and power wiring are fine.
So far I have;
- Disconnected everything except power, put the volume at 50% and turned the 4.5BT on/off to see if I can hear the main driver 'on' thump; nothing heard; there is no power at all to the main driver of the active speaker. I do hear a thump if I listen through connected headphones. So it appears the issue is internal to the speaker itself.
- Disconnected the unit from mains power, left it for a while, then power up and retry - no change.
- Checked general/Bluetooth/aux operation. In all cases, no audio from the main drivers, but it works through headphones.
My 4.5BT does not have a fuse tray at the back, and neither does it have a 110V/240V select switch; it has a single 100-240V input. Any fuse will be inside the unit.
So, it feels like a power supply issue to the driver power amplifier. Is this a simple fuse issue (and if so, where is the fuse, what is it, and is there an image of its location online), or is it a hardware fault?
Thanks in advance for any guidance on a sensible next step.