Inputs 1 & 2 on UR44C no longer functioning

So, I have a UR44 and UR44C, and I have had a similar problem occur in both interfaces. To be honest, I love the URs. Never had a single pop or crackle. Never a single issue with performance. Used them exclusively for the last decade, but, sadly, I had to switch to another interface because of this issue.

Both URs suffered the same fate this year. Now, before I go on, they were kept in a temp-controlled, dust-free, no-humidity studio. I did not use any unusual equipment with them. They were not dropped or zapped or anything like that. One day, inputs 1 & 2 on the UR44C and Input 1 on the UR44 just suddenly stopped working right, and here is what happened.

On the UR44C: Any fairly loud input signal going in on 1 and/or 2 drops out almost immediately after being heard. I’ll basically hear one note on my synth and then the input goes dead completely. I can re-plug the synth back in again, and I get the same one second of audio, but then it drops out dead again.

I did hook the UR44C up to another computer, same result, but some sound sources do not drop out, like those which have less volume and more space in between the transients, e.g., my drum machine. That seems to work fine. It only seems to happen with louder instruments that have consistent sounds. Basically, none of my synths work in those inputs now.

On the UR44: Input 1 does almost the same things as 1 & 2 on the 44C, except the audio simply gets garbled and unpleasant instead of dropping out completely. All the other inputs work fine.

I have not been able to figure out what causes this or if it simply happened as a result of some action that I’m unaware about. I will say that I almost never use Inputs 1 and 2, because I often leave them open in case I plan on using mic or guitar. So, those inputs had far less use overall.

I thought maybe there was an issue regarding balanced and unbalanced cables; I tried both, tried XLRs, same results. You hear some sound and then it’s almost like they just turn off completely. It sucks, because, technically, the UR44C outperformed my Clarett in the latency department, and the Yamaha drivers are far more stable than Focusrite’s. I just used it as an opportunity to grab an interface with more inputs, really, since the UR816C doesn’t seem to exist in the United States.

Anyways, this is not a pressing problem, but I’d at least like to know what happened to these interfaces or if they just simply wore out. So, I figured I’d put this out there. Thanks in advance to any responders.

//Edit: Is this simply because Inputs 1 & 2 are high impedance and not line? Is it actually that simple?

Fixed. 1 & 2 simply don’t take line input. Got it. Managed to get it working with an XLR from my Mixer. Problem solved.