I purchased my GROM-MST4 VOLSO4 for my 2006 Volvo S40 single CD in early January. I did the installation myself with no snags. The unit worked perfectly for most of the year until earlier this week (mid-December). Earlier this week I turned on my car and the CD player was working (it had stopped working per the instruction manual when I installed the GROM unit in January).
I tried unplugging and reconnecting the GROM unit several times. The red light coming from the connector cable is still lit. I've tried plugging the MiniDin to 3.5 mm audio in both the EXT1 and EXT2 ports but there's no change. I purchased the Bluetooth dongle kit in case it was an issue with the MiniDin cable. It arrived today and I couldn't set it up because GROM-BTD was not discoverable by my phone or other devices.
I'm also unable to use the USB port on the GROM kit to play music from my phone, which worked previously.
This unit has never had a firmware update. Could this be the problem? Any ideas why it would stop working all of a sudden? Everything seems to be connected insofar as the radio cables end. I think it may be an issue with the GROM unit itself, which is still under warranty.