AMP2 Stops working after adding touchscreen

I had a working configuration with pi3 and hifiberry AMP2. Adding the touchscreen plugin caused the AMP2 to stop working - no audio, no LEDs. It is looking like the installation of the touchscreen plugin removed or disabled the drivers for the AMP2 that are contained in the original raspian kernel. Any suggestions on resolving this issue?

Attempts to check the presence of the AMP2 on the volumio system do not indicate it is present, ie i get this

**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
Subdevices: 7/7
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
Subdevice #4: subdevice #4
Subdevice #5: subdevice #5
Subdevice #6: subdevice #6
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 IEC958/HDMI [bcm2835 IEC958/HDMI]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: ALSA [bcm2835 ALSA], device 2: bcm2835 IEC958/HDMI1 [bcm2835 IEC958/HDMI1]
Subdevices: 1/1
Subdevice #0: subdevice #0

Since the setup was working perfectly fine prior to the installation of the touchscreen drivers, something in the plug-in install damaged the driver installation for the DAC driver for the AMP2…,.

I never determined the cause for this, specifically why the AMP2 drivers disappeared when I installed the touch screen drivers and AMP2 remained non-functional. Creating a new volumio installation from scratch appears to have solved it.

Note to others. The official pi 7in touch screen requires only power (GND+5v) from the AMP2. Volumio uses the built in drivers in the kernel for the display once the plug-in is installed. If you connect the i2c lines from the GPIO header to the display as is detailed in the volumio instructions, the combination will not work - you will lose audio