Troubleshooting Zotac ITX audio dropouts.

By | January 15, 2011

Hot PCSome time ago I put together an ITX system using a Zotac GF9300-G-E.  It was the final piece to my bedroom project, except there has been one glaring issue since I got everything finished…I haven’t gotten the chance to use it!  My youngest son slept with us and he goes to bed early.  He’s not a very deep sleeper, so we stopped watching TV in the bedroom.  Recently, he started sleeping with his brother, so we’ve gotten the chance to use it.  That’s where I started encountering the first real issue.

I actually started noticing it a couple of months ago as I was watching some movies at night while my wife was either studying late or out of town.  I dismissed it at first, but after trying some different codec configurations and then even doing a complete Windows reinstall (from x64 to x86 as well) when I got the new SSD OS drive, I realized there was an actual hardware-related issue.

I knew it couldn’t be the receiver as it worked perfectly with the previous HTPC, the new in-wall speakers couldn’t cause what I was experiencing, there were no changes to my network (all other HTPCs on the upstairs trunk do not experience it) and so the new HTPC had to be the smoking gun.  Narrowing down exactly what actual component would be the problem now.  It could be the Realtek HD audio, the optical SPDIF port or even the NorthBridge chipset.

Too close for comfortI tried new drivers for everything in the system that requires them, swapped between the optical and COAX SPDIF ports and tried up-to-date nForce software…all to no avail.  That’s when I started to do some more Internet research and found that some of the Zotac ION boards have been experiencing similar issues due to overheating Northbridge chipsets.  As you can see in the image to the right, the stock Intel heatsink and fan and the Northbridge heatsink are side-by-side.  They don’t actually touch, but there is a lot of heat generated in that small amount of space.  When putting that system together, I actually took the Northbridge heatsink off and replaced the thermal pad with some good thermal compound, but if heat is causing my issues, that obviously didn’t help much.

Mounting problemI decided to remove everything (no choice as there’s no room to work in that case) and see what I could do about getting some additional cooling on that Northbridge chipset.  The first thing I noticed is that I did not install my Intel cooler in a manner that caused many to see this issue.  As the image to the right shows, some were installing their CPU cooler in a manner that caused the power lead clip to push the Northbridge heatsink just enough to cause it to not sit properly on the core…leading to overheating.  I’ve been doing this a long time and know to look for those sorts of things, but it’s very easy to do if you haven’t learned from previous bad experiences :)

New chipset fanOnce I got everything disassembled, I decided to clean the Northbridge compound off and reapply with a new layer.  I then dug out an old box of fans and heatsinks that I had and dumped it out, looking for something I could use on that Northbridge heatsink.  Luckily, I found a single 40mm chipset fan that, more than likely, came from an old motherboard that used to include them.  Anyway, a little Super Glue and reassembly and I was set to hook it back up and see if this was going to finally put an end to the problem.

I played the parking garage scene from Resident Evil: After Life and didn’t hear a single dropout (or see one on my receiver, as it will re-detect the audio format), so I’m pretty confident that it should be fixed now.  Normally, I would get a dropout every minute to a minute and a half, but in at least 5 minutes time, there were none.  A couple minutes of HD video is all it takes to get a GF9300 Northbridge good and hot, but I’ll find out for sure tonight when we watch something in its entirety.

If a search led you here due to a similar issue, providing additional cooling to your Northbridge heatsink may be all you need!


This did not resolve my issue, so I’m not sure where to turn now.  It did seem to take longer to start happening, so that may be a good sign, but once it started occurring, it was the same as always.  Not real sure how I go about additional cooling at this point, but something needs to be done.

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