Please note that we can only provide troubleshooting advice for our ready to use Pi 4 images. Due to the huge variation in PC and computing hardware, we are unable to provide direct support for custom installs other than through our forums.
## Check Channel Power Levels
By default the spectrum only shows the spectrum from CH-1. If you want to check that all channels are receiving signals correctly, under `VFO Configuration`, change the `Spectrum Calculation` value from `Single Ch` to `All Ch (TEST ONLY)`. Now in the spectrum window you will see all five spectrum graphs. Check that all graphs are receiving the signal.
Make sure you change back to `Single Ch` mode after, as the spectrum calculation mode affects how the squelcher works.
## SSH/Terminal Login
You can log into an SSH terminal by using any Terminal software (eg. PuTTY), and connecting to IP_ADDRRESS:22. The login details are "krakenrf/krakensdr. Note that if you expose port 22 to the internet, we strongly recommend changing the default password.
Alternatively, just connect an HDMI screen and keyboard, and the terminal will automatically login on boot. Note that there is no GUI, the OS is terminal only.
## Enable Logging
If you have installed the software from scratch, and suspect some issue with missing packages or similar you can enable error logging to try and diagnose the problem. Edit the daq_chain_config.ini text file with `nano ~/krakensdr_doa/heimdall_daq_fw/Firmware/daq_chain_config.ini`, and change `log_level = 2`. Log files will be written to krakensdr_doa/heimdall_daq_fw/Firmware/logs.
Also, you can enable logging on the DOA DSP software by editing the settings.json text file `nano ~/krakensdr_doa/krakensdr_doa/settings.json` and setting `logging_level = 2`.
Remember to turn logging off again by setting the logging levels to 5 after the issue is fixed, to avoid a large log file growing on the SD card.
## Tuner Test
Here we will confirm that all the tuners in the KrakenSDR system are seen by the computing device.
Connect an HDMI monitor and keyboard, or SSH into the terminal as shown above.
In a terminal window run “rtl_test -d0”. You should see a message like the following.
```
Found 5 device(s):
0: Realtek, RTL2838UHIDIR, SN: 1004
1: Realtek, RTL2838UHIDIR, SN: 1000
2: Realtek, RTL2838UHIDIR, SN: 1001
3: Realtek, RTL2838UHIDIR, SN: 1002
4: Realtek, RTL2838UHIDIR, SN: 1003
Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T/2 tuner
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
Sampling at 2048000 S/s.
Info: This tool will continuously read from the device, and report if samples get lost. If you observe no further output, everything is fine.
Reading samples in async mode...
Allocating 15 (non-zero-copy) user-space buffers
Type “CTRL” + “C” to exit the test.
```
Try again with another tuner, by running “rtl_test -d1”, and so on until “rtl_test -d4”.
If all the tuners showed similar messages, then we have confirmed that all the tuners are functional.
## Power Supply Test
Remember that the KrakenSDR **must** be powered with a 5V/2.4A+ capable external power supply. No power is provided over the USB data port.
Open four terminals, and in each individual terminal run rtl_test for an individual tuner
`rtl_test -d0`
`rtl_test -d1`
`rtl_test -d2`
`rtl_test -d3`
`rtl_test -d4`
Confirm that all tuners can be running at the same time. If there is a tuner that runs normally by itself, but fails to start when others are running then, it is likely that your power supply is providing insufficient current.
## Other things to check
* Ensure that you are using a high quality and short USB-C data cable.
* Double check with another USB device that the USB port on your computing device is not faulty.
# Android App Troubleshooting
## Bearings and Heatmap not Updating
By default, the Android app will not update when you are stationary. The start DOA button will be orange to indicate that DOA is paused due to being stationary. This is to stop bogus GPS readings from affecting results, since the GPS requires motion to calculate a heading. You can disable this setting in the Settings under `Pause Data Collection When Stationary`, or simply begin moving.
If it is not this, double check that you have the correct server address input in the settings.
Check if you can see the DOA data page at http://IP_ADDR:8081/DOA_value.html from your Android device.
