Your Android phone isn't detecting your borescope — here's the fix order

Use the scope's own cable — charge-only cables are the single most common cause

A USB cable can carry power without carrying data. The ones bundled with power banks, cheap wall chargers, hotel freebies and most "fast charging" cables sold on price are wired for power only: the data pins are either absent or not connected. Your scope will light up. Your phone will see nothing.

There's no way to tell by looking. The plug is identical. So:

• Use the cable the scope came with, or its captive cable if it has one.
• If you're using an extension or adapter, remove it entirely for this test — many USB-C to USB-A adapters are charge-only too.
• Verify a suspect cable by connecting your phone to a computer with it. If the computer offers to browse the phone's files, the cable carries data. If it only charges, it doesn't.

Do this test before anything else, even if you're certain the cable is fine.

Confirm your phone supports USB OTG (host mode)

Normally your phone is the device on a USB link and the computer is the host. To run a borescope, the phone has to flip roles and become the host: supply the 5 V, enumerate the peripheral, and drive it. That capability is called USB OTG, or USB host mode.

Most Android phones from the last decade have it. Some don't — a handful of budget and entry-level models ship without host support, and it isn't something an app can add. To check:

• Plug in any cheap USB device you already own — a mouse, a keyboard, a USB stick. If a mouse cursor appears on screen, host mode works and the problem is elsewhere.
• Search your exact model plus "USB OTG" on the manufacturer's spec page. Ignore the crowd-sourced OTG-checker apps; several report false positives.

If your phone genuinely has no host mode, no app and no adapter fixes it. A Wi-Fi borescope is the workaround — those don't touch USB at all.

Check the scope is UVC-compliant, not proprietary

USB Video Class (UVC) is the standard that lets any camera identify itself to any host in a language the host already speaks. It's why a webcam works on a computer without a driver. A UVC borescope will work with any competent Android viewer app.

Some scopes aren't UVC. They use a manufacturer's own protocol and will only ever talk to that manufacturer's own app — which, in this category, is frequently abandoned. If your scope is proprietary, no third-party app can see it, however good the cable is. Signs you have one:

• The box or manual insists you install one specific named app.
• The manufacturer's app is the only thing that has ever shown a picture.
• The scope is a Wi-Fi model — most of these are proprietary over the network rather than UVC.

Product listings that specify "UVC", "driver-free" or "works with any camera app" generally indicate a compliant device. Listings that name one specific required app generally indicate a proprietary one.

Answer the USB permission prompt — and clear a stuck default

When a USB camera is plugged in, Android shows a dialog: Allow [app] to access [device]? Nothing gets a video stream until you tap Allow. This dialog is easy to miss — it can appear behind a lock screen, or under a notification you were already swiping away.

Two things go wrong here:

• You tapped Deny once. Unplug the scope, wait five seconds, plug it back in and read the dialog this time.
• You ticked "always open" for an app you no longer use. Android then hands the scope straight to that app forever, and your current app never gets a prompt. Fix it in Settings → Apps, find the old app, and clear its defaults. On most phones that's under Open by default → Clear defaults. If the old app is one you don't need, uninstalling it clears the association outright.

Also confirm the app has been granted the Camera permission itself. A viewer app with USB access but no Camera permission will connect and show a black rectangle.

Re-seat the plug, flip it, and clean the port

USB-C is reversible in principle, but plenty of budget cables only wire one side's data pins properly. If your scope works in one orientation and not the other, that's the cable, and it will keep getting worse.

Pocket lint compacts into the bottom of a charging port and stops the plug seating fully — enough contact for charging, not enough for data. Look into the port with a bright light. If it's grey rather than black in there, that's lint. Power the phone off and lift it out with a wooden toothpick. Never anything metal.

Give it more power — or take load off the port

A borescope draws current continuously for its LEDs and its sensor, and the LED ring is the thirsty part. Bright scopes and long probes draw more. Phone ports have a hard current limit and will simply cut the peripheral off rather than exceed it.

This is what's happening if the scope works for a few seconds and then vanishes, or if it only misbehaves when you turn the brightness up.

• Charge the phone above 30%. Some phones throttle port power on a low battery.
• Turn the scope's own LED ring down to test — if it stays connected dim and drops bright, it's power.
• Drop any USB extension cable. Voltage sags over length and the cheap ones sag badly.
• For a genuinely hungry scope, use a powered OTG hub — one with its own power input — so the scope draws from the wall rather than the phone.

The Android 14 and 15 quirks most guides miss

Android's USB behaviour tightened recently, and guides written before 2024 don't mention any of it.

• Plug in with the phone unlocked. Recent Android versions can block new USB data connections while the device is locked — a defence against forensic and juice-jacking attacks. On phones and security profiles where this is active, a scope plugged in at the lock screen gets power and no data. Unlock first, then plug in.
• Check the USB mode notification. Since Android 12 the default for a new USB connection is No data transfer. Host-mode peripherals normally bypass this, but if you've been using the phone as a USB drive it can be left in a state where re-plugging behaves oddly. Pull down the notification shade and see what USB mode is reported.
• Sideloaded apps hit restricted settings. If you installed your viewer app from a file rather than a store, Android 13+ may quietly block some permissions until you allow them explicitly from Settings → Apps → [app] → ⋮ → Allow restricted settings.
• Battery optimisation kills background streams. If the feed dies whenever you switch apps or the screen dims, exempt the viewer app from battery optimisation.

Wi-Fi scopes: stop Android abandoning a network with no internet

A Wi-Fi borescope creates its own access point. You join it from the phone. That network has no route to the internet, because it's a camera on a stick — and Android notices.

When Android detects a Wi-Fi network with no internet connectivity, it will, depending on your settings, warn you, silently switch you back to mobile data, or refuse to stay joined. Your video feed dies mid-inspection for no visible reason. Fixes, in order of how often they work:

• When the "This network has no internet access — stay connected?" prompt appears, tap Yes, and tick "don't ask again for this network".
• Turn off Switch to mobile data automatically (called Adaptive Wi-Fi, Auto network switch or Smart network switch depending on the phone) in Wi-Fi settings.
• Turn mobile data off entirely for the duration of the inspection. Blunt, but it works on every phone.
• Long-press the scope's network and set it to Metered — that stops some background services fighting you for the radio.

Also worth knowing: most Wi-Fi scopes only accept one client at a time. If you handed the phone over and someone else's tablet is still joined, you'll get nothing.

Isolate it: is the scope dead, or is the phone?

Two tests settle it in a minute.

• Same scope, different phone. Works elsewhere → the problem is your phone (go back to fixes 2 and 7). Fails everywhere → the scope or its cable is dead.
• Same phone, different USB device. A mouse or USB stick proves host mode and the port are both fine.

Borescope cables fail at the strain relief, right where the cable enters the plug, because that's where they get flexed and yanked. Flex that inch gently while watching the screen. An image that flickers in and out is a broken conductor, and it isn't repairable in any practical way.