Audio Drop-Outs - how could this not be software related?

Blasty

Solder Ninja
All,

A few days ago I started experiencing some extremely disruptive audio drop-outs while watching videos. Every several minutes, the audio drops for about 0.5-1 second and then resumes. I found later that it is not just with videos, but ALL sources of audio on the computer.

I was running Kubuntu as my operating system and had no issues. Frustrated, I decided to try a fresh install of another OS (Xubuntu) to rule it out as a software issue. To my great surprise, the issue was still there! Just this evening I tried installing Debian. Same problem.

For the record, these are all clean installs. I am formatting the entire drive each time.

On the hardware side of things, the weirdness continues. I have tried audio from the 1/8" analog jack, from USB via my Schiit DAC, and HDMI through the crappy TV speakers. The periodic drop out occurs with ALL outputs!

At this point, how does one troubleshoot this issue? It shows up out of the blue as if something screwy happened in software, but multiple clean OS installs do not help. If this was a hardware issue I would have thought only one output would be affected; not all three.

I should add that I have noticed a slight hang in the mouse cursor if I happen to be moving it during the drop-out, so something is hanging up and then resuming.

Anyone else experienced similar issues with their media computer? I am hoping there is some way to pinpoint this issue so as not to end up throwing money at it.

The computer:
Shuttle DS-437 single-board fanless computer - Intel Celeron 1.8GHz
8GB RAM
120GB BP4 mSATA SSD

A very modest little box, but I have never had issues until just a few days ago. If the hardware simply wasn't capable of what I ask of it, I would think this would have happened from the beginning.
 
Enhanced speed stepping on the Celeron maybe- I had issues years ago with glitches caused by the processor slowing down during 'idle' and then switching to high speed.

I turned it off in the bios and the problems disappeared.
 
Hi John, thanks for the tip.

I went into the BIOS and disabled Enhanced Speed Stepping, but to no avail. Within a few minutes of playing a song, I got another short drop-out.

Looks like it's LPs, CDs, and browsing AK on the TV "monitor" for the rest of the night!

This computer will accept a standard 2.5" hard drive as well, so tomorrow I may stick one in and install the OS to it. At least that should tell me if my SSD is flaky. I really don't know if that could cause this sort of issue. Beyond that and the RAM, there isn't anything else I can swap out as it is all on one PCB.
 
Perhaps I overlooked it, but you did not say where your media files are stored. Are they on a NAS and you are playing files via a network?
It seems you may have covered most of your computer/OS possibilities, so maybe it has to do with your file source - just a thought.

Good luck
 
I normally use two different drives. A 4TB USB hard drive for movies and video, and a 500GB internal 2.5" drive for music.

This problem doesn't change depending on which drive I am reading from. I also removed both drives to rule them out, and still had the drop-outs when playing from Pandora over a wired network connection, or from music files on the SSD (OS drive).

I'm currently creating a live bootable USB key to bypass booting from the SSD. If the issue persists there then I think I can rule out the SSD as the culprit.

For S&G's I also installed a sensor monitor program to check temperatures. None of them seemed unreasonably high for a fanless computer, the processor runs around 40-45ºC during normal use.
 
Something is interfering with your network speed and signal continuity. Try rebooting the model and any routers. If you have a switch operating in the wired network, disconnect all inputs and outputs while the modem and routers are powered down, then reconnect prior to rebooting them.
 
The plot thickens...

When booting from a live USB drive, I was able to play music without drop-outs. I thought this had narrowed it down to an issue with the mSATA SSD, so I removed it and installed a 2.5" hard drive to which I installed the OS. And the problem is still there.

A memory test (memtest86) revealed no errors.

At this point I think this computer/motherboard itself is just hosed and there's nothing else to do. No idea what could fail like this, or why it just recently started to do it. It really does act like the system is pausing to do something and then resuming. I may hang this up for a bit and just live with it for now as I am exhausted.
 
Even when not actively using the network? Most of the time I am playing media from a hard drive; streaming very rarely.

I can certainly disconnect the network cable and see what happens though.
 
Can you abandon the SATA controller and boot from USB as well as read all your files off the USB port? If the problem is the SATA controller rather than the disk, I could see the OS polling that controller aggressively and slowing things down. Acorn makes a decent SATA to USB interface, or you can stick with the thumb drive boot and put the music as well as the movies onto the big external drive?

Looking at the Shuttle site, it looks as if they never updated the bios - double check, but it looks as if you could reflash the BIOS without actually changing anything other than resetting all the values to their defaults, so if you've made changes you'd want to make note of them before reflashing.

With the system plugged into AC, I wouldn't expect the charge state of the battery to matter, but I've seen screwy things go on when a motherboard battery needed to be replaced.
 
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oderroust - I was going to re-flash the bios as you suggested, but found out that Shuttle only provides a Windows executable. I have had success running Windows programs using WINE in the past, but no luck this time. Just for S&Gs I did reset the bios settings to the default configuration, then re-did my boot priority settings and disabled any hardware I wasn't using.

However...

You guys suspecting network issues were on to something!

There is no option in the bios to disable the wireless, and furthermore:

When I installed the OS, I was notified that there were no drivers for the wireless card. I thought it didn't matter because I was not using it, so I elected to skip manually installing them. I physically removed the card yesterday evening, and then proceeded to listen to over an hour of glitch-free music!

So I learned that even if I am not intentionally using a piece of hardware, it can cause problems just being there. I was too quick in doubting that the network could have anything to do with it.

However, I still have no idea why the problem decided to show up after more than a year of daily use like this. But it works now so who cares :).

Thank you all for your help in troubleshooting this seemingly impossible scenario!
 
Check /var/log/messages to see if anything showed up when the problem occurred. I'm thinking that you need to find and install that wireless driver, or remove the card permanently.
 
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