Wifi interface on raspberrypi zerow stopped working

Hi, after any advice - however suspect there is a hardware issue with the pi.

Brief summary - had the pi initially working fine connecting to home wifi after setting wpa_supplicant.conf in boot volume prior to starting. This had been fine for a couple of weeks. Then after a restart it failed to connect to the wifi.

After much troubleshooting trying to reconfigure a new wpa_supplicant.conf I ended up re-imaging the SD card.

I have subsequently re-imaged the SD card multiple times now. Always with the latest raspberrypi OS.

In troubleshooting things I have tried include:

  • creating new wpa_supplicant.conf file on the SD card and restarting
  • in a clean OS and connecting via SSH over USB - the raspi-config utility fails when setting wifi config with “no wifi interfaces found”
  • I have copied /etc/network/interfaces and /etc/wpa_supplicant/wpa_supplicant.conf to match another working raspberrypi and to match various internet posts. This either has no effect or upon reboot stops my ability to ssh over USB onto the device (and it doesn’t assign an IP address).

Appreciate if anyone has some suggestions.

    pi@raspberrypi:~ $ ifconfig
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 25  bytes 2392 (2.3 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 25  bytes 2392 (2.3 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

    usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 169.254.68.113  netmask 255.255.0.0  broadcast 169.254.255.255
            inet6 fe80::54f3:ddd8:b2a2:f72d  prefixlen 64  scopeid 0x20<link>
            ether 86:46:bf:37:51:03  txqueuelen 1000  (Ethernet)
            RX packets 133  bytes 28566 (27.8 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 113  bytes 13864 (13.5 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

    pi@raspberrypi:~ $ iwconfig
    lo        no wireless extensions.

    usb0      no wireless extensions.```
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Hi Adam,

Definitely sounds like a hardware issue. I know we’ve organised for a replacement but now it’s just out of interest to see if it is possible to get this working at all - and this info will help others in future!

First step with this kind of fault is to run: ifconfig -a and lsmod

Also try:
wpa_cli -i wlan0 terminate
wpa_supplicant -c /home/pi/r/test.conf -i wlan0
This will show any specific errors.

It’s worth inspecting the Wifi chip (CYW43438 - it’s the shiny one) for any signs of physical damage. I’ve seen some with almost microcscopic nicks that caused Wifi failure:

There’s also a good post on the Raspberry Pi forums here: https://www.raspberrypi.org/forums/viewtopic.php?p=1208983#p1208983

Let us know if you ever do get this working!

Regards,
Oliver
Support | Core Electronics

1 Like

Thanks - unfortunately no joy or clues from the suggestions - I’ll get a magnifying glass out but no obvious/visible damage :slight_smile:

pi@raspberrypi:~ $ ifconfig -a
lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 78  bytes 7410 (7.2 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 78  bytes 7410 (7.2 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 169.254.107.237  netmask 255.255.0.0  broadcast 169.254.255.255
        inet6 fe80::c9c2:c95a:e504:8ee5  prefixlen 64  scopeid 0x20<link>
        ether 76:cd:29:8e:84:5e  txqueuelen 1000  (Ethernet)
        RX packets 125  bytes 30458 (29.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 187  bytes 17604 (17.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

pi@raspberrypi:~ $ lsmod
Module                  Size  Used by
aes_arm                16384  1
aes_generic            40960  1 aes_arm
cmac                   16384  1
bnep                   20480  2
hci_uart               40960  1
btbcm                  16384  1 hci_uart
bluetooth             397312  24 hci_uart,bnep,btbcm
ecdh_generic           16384  2 bluetooth
ecc                    36864  1 ecdh_generic
libaes                 16384  3 bluetooth,aes_arm,aes_generic
sha256_generic         16384  0
libsha256              20480  1 sha256_generic
cfg80211              671744  0
rfkill                 28672  4 bluetooth,cfg80211
8021q                  32768  0
garp                   16384  1 8021q
stp                    16384  1 garp
llc                    16384  2 garp,stp
raspberrypi_hwmon      16384  0
bcm2835_codec          36864  0
v4l2_mem2mem           32768  1 bcm2835_codec
bcm2835_v4l2           45056  0
bcm2835_isp            28672  0
bcm2835_mmal_vchiq     28672  3 bcm2835_isp,bcm2835_codec,bcm2835_v4l2
snd_bcm2835            24576  1
videobuf2_dma_contig    20480  2 bcm2835_isp,bcm2835_codec
videobuf2_vmalloc      16384  1 bcm2835_v4l2
videobuf2_memops       16384  2 videobuf2_dma_contig,videobuf2_vmalloc
videobuf2_v4l2         28672  4 bcm2835_isp,bcm2835_codec,bcm2835_v4l2,v4l2_mem2mem
videobuf2_common       53248  5 bcm2835_isp,bcm2835_codec,bcm2835_v4l2,v4l2_mem2mem,videobuf2_v4l2
snd_pcm                94208  1 snd_bcm2835
snd_timer              32768  1 snd_pcm
snd                    69632  5 snd_timer,snd_bcm2835,snd_pcm
videodev              225280  6 bcm2835_isp,bcm2835_codec,videobuf2_common,bcm2835_v4l2,v4l2_mem2mem,videobuf2_v4l2
vc_sm_cma              32768  2 bcm2835_isp,bcm2835_mmal_vchiq
mc                     45056  6 bcm2835_isp,bcm2835_codec,videobuf2_common,videodev,v4l2_mem2mem,videobuf2_v4l2
uio_pdrv_genirq        16384  0
uio                    20480  1 uio_pdrv_genirq
fixed                  16384  0
usb_f_ecm              16384  1
g_ether                16384  0
usb_f_rndis            28672  2 g_ether
u_ether                20480  3 usb_f_ecm,g_ether,usb_f_rndis
libcomposite           57344  3 usb_f_ecm,g_ether,usb_f_rndis
dwc2                  163840  0
udc_core               53248  5 usb_f_ecm,dwc2,u_ether,usb_f_rndis,libcomposite
ip_tables              28672  0
x_tables               32768  1 ip_tables
ipv6                  446464  20
nf_defrag_ipv6         20480  1 ipv6

pi@raspberrypi:~ $ wpa_cli -i wlan0 terminate
Failed to connect to non-global ctrl_ifname: wlan0  error: No such file or directory

pi@raspberrypi : ~ $ cat /home/pi/wpa_supplicant.conf

ctrl_interface=/run/wpa_supplicant
update_config=1
country=AU

network={
ssid="houpla"
psk="XXXXX"
}

pi@raspberrypi :~ $  wpa_supplicant -c /home/pi/wpa_supplicant.conf -i wlan0

Successfully initialized wpa_supplicant
Could not read interface wlan0 flags: No such device
nl80211: Driver does not support authentication/association or connect commands
nl80211: deinit ifname=wlan0 disabled_11b_rates=0
Could not read interface wlan0 flags: No such device
Could not read interface wlan0 flags: No such device
Could not read interface wlan0 flags: No such device
wlan0: Failed to initialize driver interface
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