Hi
What exact driver and firmware versions do you have installed? 'Latest version' is not precise because after publishing new versions it’s not the same anymore…
Also the exact macOS version can matter.

Have tested on an older windows laptop with similar results, although audio gets more distorted and fades away completely after a few seconds.
Guess it's a hardware issue, wonder if it's still worth having it repaired since it's 10+ years old now?

I do not know your requirements and your budget situation, but if I were you, then I would consider to get the new UCX II to get all the fantastic new features. A lot has happened in the past 14 years.

The UCX II costs now €1375+. I would repair and sell the UC to cross finance the purchase.

I assume that repair won't cost that much and that you will get around 65% of the former street price plus a little on top because everything became pricier. Everybody knows about the very long driver support of RME and as it has just been repaired, it will run again for many years without issues.

So, there should be a quite nice amount of money left for cross financing the purchase.

Quick overview about the different UC-style interfaces since 2009 (UC -> UCX -> UCX II)
and the advantages of UCX II over UC and UCX.

[ see also my Excel here: https://forum.rme-audio.de/viewtopic.ph … 6#p186126) ]

The UC was introduced in 2009 (14y ago) as a pure USB interface and without FX-chip

Three years later, in 2012 (11y ago) the UCX was introduced.
- support for USB and Firewire
- 3-4x faster converters (14 / 7 samples latency @44.1 vs. UC: 43 / 28 samples AD/DA)
- FX-chip
- Autoset feature
- Class Compliant mode
- 6 recallable stand-alone profiles

9y later in 2021 (2y ago) also the UCX got a successor with again new outstanding features compared to the UCX
- support for USB
- even faster converters, 5-9x ( 5 / 6 samples latency @44.1 vs. UC: 43 / 28 samples AD/DA)
- much better display comparable to UFX II/III, completely operable via the display
- DURec support (as stand-alone recorder or as backup for DAW recording)
- track names for DURec
- preamps with up to 75 dB gain (like UFX II flagship interface)
- better headphone outputs
- Additional AES port (nice for integration of ADI-2 DAC/Pro ADI2/4 Pro SE, you still have ADAT port free for add preamp etc)
- overall better analog section
- Instr inputs with 1 MOhm
- re-mappable and lockable keys (comparable to ADI-2 DAC/Pro)
- of course same features like UCX
- full implementation of FX-chip
- Autoset feature
- Class Compliant mode
- 6 recallable stand-alone profiles