High levels of white noise

Hello, I’ve been having this problem with my recording.

Basically when recording with my microphone the signal often has a lot of noise on it and sometimes is completely ruined by white noise and the waveform looks like a chunky rectangle with spikes coming off it. Also when I have recorded with nothing plugged in inputs wise (no mic,no guitar) and did a recording, this still happens sometimes. At the moment recording with a guitar plugged in seems to not be affected.

Forgot to say, I use a UR22, which is why it might be relevant to this forum! I got it 3 years ago so I think it is a mk1.

Any help is much appreciated.

Thanks