Serious connectivity issues

Hi guys
I use musicbox on pi b+ with hifiberry and wifi. The problem I have is, that the box keeps losing connection (ssh and musicbox) ever so often that it is pretty useless at the moment. I keep putting a new image in the card again and again but to no avail. Can someone point me in the right direction what to do ? Are there error logs or something similar ?
Thanx for reading

Try a different power supply. Try a wired connection. Try a different wifi

tried a different power supply and another pi. could not experiment with another wifi dongle yet.
what i observe is that last night everything worked fine. when i tried to access musicbox.local in the morning same problem: no connection. not even via ssh. i needed to reboot - then everything went fine.
any clues?
thanx for reading!!!

You probably need to spend some time examining your system log files to get
to the bottom of that.

And try a wired connection.

you mean cd /var/log? or mopidy logs?

Since you appear to have lost all connectivity, I would suggest system logs
in /var/log