Hey, keithguitarfan –
I experienced something pretty much identical to this last year with my Axe-FX II. It wound up being nothing at all… but since I was still under warranty, and curious about what was going on, I opened a support ticket. I'm going to cut & paste the interaction here, just so you can have it as a reference. I know it's a lot, but I thought it might help put your mind at ease.
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(from randyman) Hi there! I upgraded from an Ultra to a new Axe-FX II mkII last October, and I love it. It's worked flawlessly, and continues to work flawlessly despite the concern I'm reporting.
I'm writing because about a month ago, I started to notice a distinct characteristic smell of hot or burning electronics after I turn it on. It seems to peak a few minutes after I turn it on, or perhaps I just acclimate to it. The unit itself continues to work just fine, with no evidence of intermittent or erratic behavior. The smell isn't severe; it's simply noticeable, and definitely has only shown up recently. There is no visible smoke or anything of the sort.
It doesn't seem to be temperature related. The unit is rack mounted, but there is an empty rack space above it, and nothing below it. The practice room is cool, often with the window open and a nice breeze. I can hear the Axe's fan running quietly when I put my ear near the unit.
I haven't yet removed the unit from the rack to open it, and see if anything is visible. One of the reasons I'm writing is to see if you think I should try that. I'm also coming up on a year of ownership, so I thought that if there was an issue, I should probably bring it up while under warranty.
As I said, it really isn't much of a bother; it just began so suddenly that it seemed to indicate something had happened. It definitely wasn't there for the first eight or so months I had the unit.
Well, that's it. I do want to thank you all for your fantastic work, and the unbelievable amount of ongoing effort you continue to put in to upgrading firmware and software. It's like Christmas twelve months a year!
(from Matt in Support)
The main heat source inside an Axe-Fx is the CPU, which is cooled by a fan. Please have a local tech remove the cover and check to see that the fan is properly in place and spinning. Thanks for the other nice things you had to say by the way.
(from randyman)
Hi, Matt – thanks for the fast response, even on a holiday weekend! Be sure not to stay indoors too long today.
There was no need for a tech; I've been doing hardware mods on my synths for decades. I opened the Axe-FX, and wow – what a gorgeous, clean and efficient use of space. The fan was right where it's supposed to be, spinning away and doing its thing. The heat sinks on the CPU seemed to be firmly seated, though one looked *very slightly* rotated in place; maybe 1/32 to 3/64 of an inch at the corners.
I went over every inch of the interior with a flashlight; there was nothing amiss whatsoever. No heat discoloration, no blown capacitor or resistor; everything looked immaculate. I tried sniffing around the boards, but couldn't pinpoint the location of any scent. And as I mentioned, once I acclimate to it, the scent pretty much goes away.
However, I do know that at one point about a month ago, there was a sudden noticeable smell; enough to make me wonder what was going on. If I had to make a guess – and this is just an uninformed shot in the dark – perhaps a combination of spring tension on the clip holding the heat sink down, and eight months of the thermal grease being exposed to heat allowed the heat sink to suddenly shift slightly, releasing the scent I noticed.
Or I could just be paranoid and making something out of nothing. At any rate, everything looks fine, the Axe works perfectly, and the scent has greatly decreased over time. It's really barely noticeable compared to a month ago, and even then it was pretty minor.
So thanks for your help; at this point I'm pretty much satisfied that there is no issue. At least I've done my due diligence.
Enjoy the rest of the holiday weekend!
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Funny that this involved another holiday weekend; that was last Labor Day.
That smell was definitely something I noticed at the time, but seeing your post made me realize that it's been completely gone for months. You may want to open the box and see if you can locate anything, and by all means – look at your heat sink carefully, and see if it's shifted at all – even by a minute amount.
My Axe is still in glorious working condition, so I hope my experience will bring you some peace of mind.
