When an IP camera shows no live image on a tester, browser, VMS or NVR, work through the layers in order: **power → Ethernet link → IP access → camera stream → RTSP → tester or NVR**. Don't change stream settings until power and network are confirmed — fix the first layer that fails, then move on.
## Quick diagnosis
Answer these in order and stop at the first "no":
1. [Does the camera have power?](#no-power)
2. [Is there an Ethernet link?](#no-link)
3. [Can you reach the camera by IP?](#not-found)
4. [Does the camera show video in its own interface?](#no-video)
5. [Does the RTSP stream play directly?](#rtsp)
6. [Does it play on the tester or NVR?](#nvr)
---
## 1. No power {#no-power}
**Quick check:** Power-cycle the camera, cover the light sensor and watch the IR LEDs (on cameras with IR). If they light up, the camera has power — skip to section 2.
**DC-powered camera**
- Check the adapter's indicator, then try a known-good 12V supply.
**PoE-powered camera**
- Try a known-good PoE port or injector.
- Check the switch's per-port PoE status and remaining power budget.
- If a DC supply is available, use it to confirm the camera itself works.
**If the camera boots on a known-good source,** the fault is upstream: cable, connector, switch or injector, PoE budget, or adapter.
**Tester shortcut:** Power the camera directly from the tester's PoE or 12V DC output. If it boots, you've isolated the problem to the original power path in one step.
**Move on when:** the camera powers up and boots normally.
---
## 2. Power, but no Ethernet link {#no-link}
A powered camera isn't necessarily connected. Check the link LED on the switch or NVR port — solid or flashing means a physical link; off means none.
**If there is no link:**
- Inspect the RJ45 connectors for oxidation, looseness or poor crimping.
- Swap in a known-good patch cable and a known-good port.
**If a known-good cable and port restore the link,** the fault is in the original cable, connector, patch panel or port. **If the link stays down,** inspect the camera's Ethernet interface.
**Tester shortcut:** A cable test shows opens, shorts and miswiring; with TDR, it also estimates the distance to the fault.
**Move on when:** the port shows a stable link.
---
## 3. Link is up, but the camera can't be found {#not-found}
A link light only proves the physical connection. Next, confirm the camera and your computer or tester can talk at the IP layer.
**Check the addressing.** Record the camera IP, your device IP, subnet mask and gateway. For example, a camera at `192.168.1.120` and a laptop at `192.168.1.50` with mask `255.255.255.0` can talk directly; a laptop on `192.168.0.x` can't without a router.
**If you don't know the camera's IP,** try in order:
1. The client list on the router, PoE switch, NVR or DHCP server.
2. The manufacturer's discovery tool.
3. A LAN scanner or ONVIF discovery tool.
4. The model's default IP, if the camera was just factory-reset.
**Once you have the IP,** open it in a browser, connect with the manufacturer's client, or ping it. A failed ping doesn't prove the camera is offline — some devices and networks block ICMP.
**If it's still unreachable,** look for:
- Wrong subnet, mask or gateway
- Unknown static IP, or a switch between static and DHCP
- IP address conflict
- VLAN or port isolation, ACL or firewall rules
- A changed management port
**Tester shortcut:** IP scan and ONVIF discovery find the camera without changing your laptop's IP or installing software.
**Move on when:** you can open the camera's web interface or client.
---
## 4. Camera is reachable, but shows no video {#no-video}
Reaching the camera proves power, link and IP are working. Now confirm the camera is producing a usable stream.
**Check video in the camera's own interface first** — its web page, the manufacturer's client, or an NVR preview. Verify:
- The video channel and stream are enabled
- The user account has live-view permission
- Codec (H.264, H.265/HEVC, sometimes MJPEG), resolution, frame rate and bitrate
**Compare main stream and sub-stream.** If the sub-stream plays but the main stream doesn't, the camera is working — the likely cause is decoding capability or stream settings. For example, a 4K H.265 high-bitrate main stream fails while a 720p H.264 sub-stream plays: focus on the client, not the cable or PoE.
**If there's no image even in the camera's own interface,** the fault is on the camera side. Check that it has finished booting, then review firmware, sensor status, privacy masks and the camera's logs. Repeated reboots or hardware errors call for the manufacturer's procedure.
A blank browser view alone doesn't prove anything — many cameras use codecs or plugins browsers can't display. Confirm with a manufacturer client, RTSP player, ONVIF client, NVR or tester.
**Tester shortcut:** Live preview on the tester confirms the camera is streaming without a PC, browser plugin or NVR.
**Move on when:** you can see video from the camera directly.
---
## 5. Camera works, but RTSP won't play {#rtsp}
The camera's web view and its network stream are separate. Test the RTSP stream directly and verify:
- Camera IP and RTSP port (default 554)
- Stream path for main and sub-stream
- Username and password
- Codec (see section 4)
If the main stream fails, try the lower-resolution sub-stream.
**If direct RTSP playback fails,** check the RTSP settings, credentials, stream URL and codec on the camera. **If it plays,** the camera and stream are fine — the problem is the NVR, VMS or tester configuration.
**Tester shortcut:** RTSP playback tests the stream without a recorder, separating camera faults from NVR or VMS faults.
**Move on when:** the RTSP stream plays directly.
---
## 6. RTSP works, but there's no video on the tester or NVR {#nvr}
At this point power, link, IP and the stream are all proven. What's left is configuration, authentication, stream selection or compatibility.
**Check:**
- Camera and ONVIF user credentials
- ONVIF service enabled, and the selected media profile
- Main vs. sub-stream, and whether the client supports its codec, resolution and frame rate (see section 4)
- NVR channel settings
Try adding the camera manually by IP with known stream settings, or switch to a lower-resolution H.264 sub-stream to rule out decoding limits.
**Common patterns:**
- **ONVIF finds the camera, but no video:** discovery doesn't validate credentials, media profile or codec — test the stream directly.
- **RTSP works, but ONVIF integration fails:** check the ONVIF configuration, user and media profiles, or client compatibility.
- **Works on one client, not another:** the failing client's settings or supported formats are the issue.
**Tester shortcut:** ONVIF testing discovers the camera, reads its media profiles and checks interoperability before you involve the recorder.
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## Find the right tester
For cable TDR, SDI or high-power PoE, use the [Tester Finder](/tester-tools/finder) to match a model to your workflow.