Xantia speedometer suddenlly going to 0 and suddenly working again

[Hadmund]

I've been trying to diagnose what the issue with my Xantias speedometer. While driving it randomly drops to 0 and stays there until i randomly starts working again. I haven't been able to find anyone with this exact issue so i've been struggling to find out what the cause might be.
From what ive read there is a similar problem that can occur where it will jump to 50 mph and stay there. My understanding is that this is usually because of cracks forming on the pcb of the speedometer, however when inspecting mine i didn't find anything like that. Mind you my inspection may not have been the best as i tried doing it with the naked eye and didn't take of the actual motor mechanism that drives the needles, i only looked at the backside of the whole speedometer pcb.

My current theory is that its a faulty sensor, so i'm going to reinstall the speedometer and hope I don't need to pull the whole thing out again.

[Stickyfinger]

The cracks on my PCB were ---tiny--- and I had to use a 10x magnifying head set to see them....