Raspberry3 WLAN 'invisible'

[Toulon7559]

My Raspberry3 crashed.
After re-installation of the software the Raspberry refuses to connect to the WLAN.
First tried with dhcp, with MAC-filtering in the router, but no visible connection: the Ip-address does not show on the WLAN.
Then tried to implement a fixed IP-address for Raspberry's WLAN-interface by all 'usual' trics to set /etc/network/interface, /etc/dhcpcd.conf and /etc/wpa_supplicant/wpa_supplicant.conf, but the commandline-command ifconfig wlan0 still shows

Code: Select all

wlan0     Link encap:Ethernet  HWaddr b8:27:eb:68:51:fc
          inet addr:169.254.64.31  Bcast:169.254.255.255  Mask:255.255.0.0
          inet6 addr: fe80::da71:960f:6c1c:97a4/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:988 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:82087 (80.1 KiB)

Looking at the IP-address and Bcast-address, have the impression that the Raspberry simply does not make any connection to WiFi.
Anybody a possible solution?

[Toulon7559]

After comparison with other Raspberries, and subsequent some fiddling with files /ets/network/interfaces, /etc/dhcpcd.conf and /etc/wpa_supplicant/wpa_supplicant.conf found the 'culprits':
some extra lines added to those files [intended as 'improvement' after reading the various websites on this aspect] caused the 'blackout' of the wlan0.
Reduced back to basic minimal contents in those 3 files, and now wlan0 operates again .......