Whilst updating a Pi3 on stable.
Oct 15 11:20:33 zynthian-amp startx[489]: gpio: Unable to open GPIO direction interface for pin 7: No such file or directory
Oct 15 11:20:33 zynthian-amp startx[489]: wiringPiISR: unable to open /sys/class/gpio/gpio7/value: No such file or directory
Don’t remember seeing that one before. But it’s about to get a new SSD so it might stop complaining.
Caused by use of a previously working GPIO direct connected Encoders as per :
With wiring selected and above pins it fails to start with above line.
I’ll log a bug.
Caused by spi mode being enabled in raspi-config…
The pin involved was the only pin i’d used in the SPI block GPIO 7,8,9,10,11
D’Oh !
So did you chose different pins or disable SPI? If the latter please share with the class.
Disabled SPI in raspi-config.
Mind you it’s a right old fight as the pi keeps rebooting and you don’t get webconf for more than 10 seconds or so…
Still fighting pin 11 & audio device.
I think this Pi is in for a new stable build.
It’s now working at last …
now that was a bug!! 
Ok.
Rebuilt on a clean stable…
Configured.
Wouldn’t start.
Updated.
Switched to testing.
Added audio card hifiberry Amp…
Started . . .
Configured wiring as per attached … Same problem …
Turned off SPI in raspi-config now works . . .
So there is something about the hifiberry amp settings and the SPI mechanism…
After a bit of soldering …
Moving the Prviously pin 26, connected to the Back switch to Pin 10 and including 16 in the 2nd position of the Switch settings, we have a functioning zynthi…
And it reboots cleanly!
I notice we have the timeout power off back !! Nice.
updated zynthian-alm.local
25,26,4,0
27,21,3,7
23,16,2,22
