Smart home technician helping fix Google Home / Nest Hub black screen

Steve H.

Expert ★★★★★ 27,853 satisfied customers

Specialities: Chromecast and Google Cast issues, TV and smart speaker discovery problems, Wi-Fi setup, router settings, Local Network permissions.

Common reasons the Cast button appears but no TV or speaker is found, and the safest checks to start with

Technician avatar Technician
Let’s check this safely first. I do not want you changing router settings right away if the problem turns out to be something smaller.

Did this start today, or has casting worked before on the same phone and same TV or speaker?
Customer
It worked before. Now the Cast icon is there in my apps, but it just keeps searching and never finds anything.
Technician avatar Technician
That detail matters. If the Cast icon still appears, the app itself still supports casting, so we should focus on discovery between your phone and the device.

What changed recently: new router, guest Wi-Fi, software update, phone replacement, or did the TV or speaker get unplugged?
Customer
My phone updated a few days ago. I also restarted the router yesterday, but the Wi-Fi name stayed the same.
Technician avatar Technician
That gives us two likely paths already: a phone permission change after the update, or the phone and cast device ending up on different parts of the network after the router restart.

Trust moment: this is common after updates, but we should rule out risks before touching anything bigger.

Is your TV or speaker powered on fully right now, and is it connected to Wi-Fi as far as you can tell?
Customer
Yes, the speaker is on and it responds to voice commands. The TV is on too, but neither one shows up in casting.
Technician avatar Technician
That is useful because it makes a full device outage less likely. If the speaker still responds, it usually means the device is alive and on the network, but your phone may not be allowed to discover it.

On your phone, are you connected to the main home Wi-Fi, or could you be on a guest network, extender network, VPN, or mobile data fallback?
Customer
I am on home Wi-Fi, but I do have a VPN app on my phone. I am not sure if it is active.
Technician avatar Technician
That can interfere with device discovery. Casting depends on your phone being able to see nearby devices on the local network, so VPNs, Private Relay, or strict privacy settings can interrupt that scan.

Another safe check: did your phone recently ask for “Local Network” permission for the app you are casting from or for Google Home, and maybe get denied?
Customer
I remember a permission prompt after the update, but I may have tapped no without thinking.
Technician avatar Technician
That is a strong clue. The Cast icon can still appear in apps even when the app is not allowed to look for devices on your local network, which makes it feel like the TV or speaker vanished.

Let’s keep this simple: do you see the speaker or TV inside the Google Home app itself, or has it disappeared there too?
Customer
The speaker shows up in Google Home, but the casting apps still do not find it.
Technician avatar Technician
That narrows it down nicely. If the device still appears in Google Home, the network path is probably there, and the problem may be more app-specific or permission-related on the phone rather than the speaker being offline.

I do not want you trying random resets that could make this harder. One thing I would check next is whether the affected apps have local network access and whether the VPN is paused during discovery.
Customer
That makes sense. My streaming app cannot find anything, but Google Home still sees the speaker.
Technician avatar Technician
Then this may be a misleading issue rather than a broken cast device. People often assume the TV or speaker dropped off Wi-Fi, but sometimes the phone app simply loses permission to discover local devices after an update.

One more check: are you using the same Wi-Fi band and same network on the phone as before, or does your router have a guest network or separate 2.4 GHz and 5 GHz names now?
Customer
There is a guest network, but I am not on it. The router also has one name for both bands.
Technician avatar Technician
That setup usually works, but after router restarts or updates, discovery can become inconsistent if the phone and cast device land on different paths or the app loses the ability to scan the network.

The safest reading of your symptoms is this: the cast device is probably still online, but your phone is not completing discovery properly. That points more to local network access, VPN/privacy filtering, or network isolation than to hardware.
Customer
So I should think permissions and network discovery first, not that the speaker or TV is broken?
Technician avatar Technician
Yes, that is where I would look first based on what you described. The Cast icon appearing but finding nothing often means discovery is being blocked somewhere, not that every device failed at once.

If you want to narrow it down further, compare whether Google Home sees the device, whether the same problem happens in more than one app, and whether it changes when privacy tools or network filters are paused.

Quick answer: the accepted fix

When the Cast icon appears on a phone but no TV or speaker is found, the issue is often device discovery rather than a dead cast device.
• Check whether the phone and the cast device are on the same home network and not split across guest Wi-Fi, VPN, or another path.
• Review Local Network permissions for the app you are casting from and for Google Home, especially after a phone update.
• Compare what happens in Google Home versus streaming apps; if one sees the device and the other does not, that points to an app or permission issue.
• Treat router restarts, privacy settings, and mesh isolation as possible causes before assuming the TV or speaker hardware is failing.

Why the Cast icon can show up even when no devices appear

A Nest Hub black screen can look scary, but it’s usually one of a few repeat issues: unstable power (wrong adapter, failing brick, loose cable, power strip problems), display settings (Night Mode, extremely low brightness, auto-brightness/Ambient EQ going too dim), or a firmware/UI hang after the device is moved or unplugged. If your Google smart display is blank but still answers voice commands, it often points to a display/UI problem rather than Wi-Fi. If the screen is fully black with no glow and you never see a boot logo, treat it as either a serious firmware hang (fixed by reset) or a hardware backlight/display fault (needs support).

What to check first if your phone keeps searching for cast devices

After the reboot or reset, confirm the fix in a few quick ways: you should see the “G” logo at startup, the display should show the clock/photo frame, and the touchscreen should respond to swipes. In the Google Home app, open your Nest Hub device settings and verify brightness is above 50% and Night Mode is off. Try a few commands like “Hey Google, show the weather,” “set brightness 70%,” and cast a short audio track. If it stays stable for a few hours (including after unplugging/plugging back in), and the screen wakes normally, you’ve likely solved the Google Home black screen issue.

Cast icon appears, but no TV or speaker is listed

Common reasons include local network permissions, VPN/privacy filters, network mismatch, or discovery issues after updates.

Quick path: use the original adapter and a direct wall outlet, unplug for 60 seconds, then check the Nest Hub’s display settings in the Google Home app (Night Mode, brightness, auto-brightness). If your Nest Hub screen is black but it still talks, a proper factory reset is usually the fastest way to restore the display. If there’s no backlight and it stays black even after reset, contact official support — that’s when it’s likely a hardware display/backlight issue.

Disclaimer: This information is AI-generated and intended for general guidance only. Do not open the device or attempt internal repairs. For advice specific to your Google Nest model and setup, consult a verified expert or official support before making decisions.

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FAQ

Why does the Cast icon show up but never find my TV or speaker?

The icon can still appear even when discovery is blocked. Common reasons are Local Network permission, VPN or privacy filtering, and the phone or cast device being on different network paths. It does not always mean the TV or speaker is offline.

Did this start after a phone update?

Yes, that can happen. Updates sometimes reset or change network permissions for apps. If Local Network access was denied, apps may keep showing the Cast button but fail to list devices.

Is this a settings issue or hardware?

Most of the time it is a settings or discovery issue, not hardware. If the device still appears in Google Home or responds normally, the hardware is usually fine. The problem is often between the phone and the local network scan.

Can this be checked safely at home?

Yes. Start with simple checks like confirming the phone is on the main Wi-Fi, reviewing Local Network permissions, and pausing VPN or privacy tools. Avoid factory resets until you know whether the device is still visible in Google Home.

Sources

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