shumphreysmusic

@theElevators - Yeah, the clicking and popping 5mafr5br reports in his post does sound like a cable issue, potentially. For me, this is not acting at all like a cable issue. This output cable (and the guitar cable) is a relatively new cable that I keep as a backup, just a few years old, good quality, and lightly used a few times, always carefully "union wrapped" (over/under), and not stepped on much - mostly routed out away from where we stand. The connections and plugs are in great shape. There's heat shrink around the solder joints so I can't see the connections, but it's all clean, no damage to the heat shrink, strain reliefs and jacket or plugs. The sound just cut out all at once, no hint of an issue, no crackles, etc. ever before that. The input and output blocks were responding to the guitar, so with the power still on we swapped in a different output cable to the PA with no improvement, still dead. After power cycling both the swapped and original cable worked fine. This is acting most like an output protection circuit tripped, perhaps a thermal shut off tripped, though I run at half volume for the line out (so most of heat is probably in the processor(s)), or possibly power-on-reset tripped and reset a processor or a serially programmed device like an active resistor type of component in the output chain. I'm not familiar with the architecture enough to say more specifically what it could be, but it's that kind of an immediate reset or "shut off" behavior. A mains surge, high noise or droop might cause this type of thing if the internal DC power supply is not well filtered and bypassed, for example. Switching presets, which I imagine should reprogram every stage, did not bring the output back, only a full power cycle. If there is some sort of event log to check later that would be really helpful for debugging. Not sure if the Helix LT provides any? Cheers

Just the floor unit with guitar in, one line out, and power being the only connections. (Good question to clarify the situation.) edit- Also, this was while in the middle of playing a song, not immediately after any switch press or adjustment including the expression pedal. If this occurs again, are there any other steps that might help isolate the problem? For example, I switched presets and a few switches for snapshots and bypasses to no effect (output sound was still dead).

Just posting to say I had this problem tonight at rehearsal, as well. Updated to 3.71 a month ago, and never had this occur before. The sound stopped coming out on the left/main out (1/4" jack). The display and switch functions were working normally, and the input and output blocks on the screen showed signal (blank to green shading when playing). A power cycle fixed it. (off, wait 10 seconds, power on). I'm wondering if a UPS or other supply conditioner might be a good idea.

Replying to my own post here. The problem is resolved after updating to 3.6! Perhaps one of the 'minor issues' fixed in the 3.6 firmware was to improve the rotary encoder routine? (I've worked on this type of code before, and debouncing is not straightforward.) Cheers. edit - Not sure what Jadea61 has run into, as it's backwards from mine. Perhaps try rolling back to 3.5 and see if the knob works again? (Maybe there is still some lack of robustness with the rotary encoder decoding.)

I'm having exactly this problem on a Helix LT knob 4, and I did update to 3.5. I just purchased new but scratch/dent from a major retailer. I can't say for certain that the knob 4 was working before, but seems like quite a coincidence. All other knobs are working. I'll try a factory reset again and the down grade over the next few days.