Dell laptop won't display external monitor

[royt911]

I just updated the kernel and it didn't help. This Dell has an Fn + F1 option to switch monitors. It don't work. I go to display settings and it says mirrored displays. But I get nothing on the tv. Any ideas?

System:
Kernel: 5.11.0-36-generic x86_64 bits: 64 compiler: N/A
Desktop: Cinnamon 5.0.5 wm: muffin dm: LightDM Distro: Linux Mint 20.2 Uma
base: Ubuntu 20.04 focal
Machine:
Type: Portable System: Dell product: Inspiron 3521 v: A12 serial: <filter>
Chassis: type: 8 v: A12 serial: <filter>
Mobo: Dell model: 0X2H5X v: A00 serial: <filter> UEFI [Legacy]: Dell
v: A12 date: 10/25/2013
Battery:
ID-1: BAT1 charge: 22.7 Wh condition: 30.1/41.4 Wh (73%) volts: 15.8/14.8
model: Simplo DELL FW1MN31P serial: <filter> status: Discharging
CPU:
Topology: Dual Core model: Intel Celeron 1017U bits: 64 type: MCP
arch: Ivy Bridge rev: 9 L2 cache: 2048 KiB
flags: lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 6385
Speed: 814 MHz min/max: 800/1600 MHz Core speeds (MHz): 1: 814 2: 1015
Graphics:
Device-1: Intel 3rd Gen Core processor Graphics vendor: Dell driver: i915
v: kernel bus ID: 00:02.0 chip ID: 8086:0156
Display: x11 server: X.Org 1.20.11 driver: modesetting
unloaded: fbdev,vesa resolution: 1280x720~60Hz, 1280x720~60Hz
OpenGL: renderer: Mesa DRI Intel HD Graphics 2500 (IVB GT1)
v: 4.2 Mesa 21.0.3 compat-v: 3.0 direct render: Yes
Audio:
Device-1: Intel 7 Series/C216 Family High Definition Audio vendor: Dell
driver: snd_hda_intel v: kernel bus ID: 00:1b.0 chip ID: 8086:1e20
Sound Server: ALSA v: k5.11.0-36-generic
Network:
Device-1: Realtek RTL810xE PCI Express Fast Ethernet vendor: Dell
driver: r8169 v: kernel port: 2000 bus ID: 01:00.0 chip ID: 10ec:8136
IF: enp1s0 state: down mac: <filter>
Device-2: Broadcom and subsidiaries BCM43142 802.11b/g/n
vendor: Dell Wireless 1704 802.11n + BT 4.0 driver: wl v: kernel
port: 2000 bus ID: 02:00.0 chip ID: 14e4:4365
IF: wlp2s0 state: up mac: <filter>
Drives:
Local Storage: total: 465.76 GiB used: 277.45 GiB (59.6%)
ID-1: /dev/sda vendor: Western Digital model: WDBNCE5000PNC
size: 465.76 GiB speed: 6.0 Gb/s serial: <filter>
Partition:
ID-1: / size: 456.95 GiB used: 277.45 GiB (60.7%) fs: ext4 dev: /dev/sda5
Sensors:
System Temperatures: cpu: 44.0 C mobo: N/A
Fan Speeds (RPM): cpu: 0
Repos:
No active apt repos in: /etc/apt/sources.list
Active apt repos in: /etc/apt/sources.list.d/official-package-repositories.list
1: deb http://packages.linuxmint.com uma main upstream import backport #id:linuxmint_main
2: deb http://archive.ubuntu.com/ubuntu focal main restricted universe multiverse
3: deb http://archive.ubuntu.com/ubuntu focal-updates main restricted universe multiverse
4: deb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse
5: deb http://security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse
6: deb http://archive.canonical.com/ubuntu/ focal partner
Info:
Processes: 193 Uptime: 20m Memory: 3.73 GiB used: 1.15 GiB (30.8%)
Init: systemd v: 245 runlevel: 5 Compilers: gcc: 9.3.0 alt: 9
Shell: upload-system-i running in: gnome-terminal inxi: 3.0.38

[SMG]

I just updated the kernel and it didn't help. This Dell has an Fn + F1 option to switch monitors. It don't work. I go to display settings and it says mirrored displays. But I get nothing on the tv. Any ideas?

Graphics:
Device-1: Intel 3rd Gen Core processor Graphics vendor: Dell driver: i915
v: kernel bus ID: 00:02.0 chip ID: 8086:0156
Display: x11 server: X.Org 1.20.11 driver: modesetting
unloaded: fbdev,vesa resolution: 1280x720~60Hz, 1280x720~60Hz
OpenGL: renderer: Mesa DRI Intel HD Graphics 2500 (IVB GT1)
v: 4.2 Mesa 21.0.3 compat-v: 3.0 direct render: Yes

Usually, the cases where we recommend updating to a newer kernel are ones where the hardware is newer and needs a driver which is only available in the newer kernel. I would not think that is the case for your cpu, but if the newer kernel seems to work okay you can continue using it.

It appears the X Server is picking up the fact there are two monitors. Do those resolutions I highlighted in blue look correct to you? The specs I found for Dell Inspiron indicates it has a 1366x768 resolution.

Are both displays showing in the Displays app?