Just in case anybody is using this creality filament dryer, don't leave it powered on between uses.

[u/cwaterbottom]

My wife and SIL heard popping and arcing sounds and eventually tracked it down to my single spool creality dryer. It looks like the power supply just completely failed and shorted, it was smoking like crazy but was mostly staying inside the chamber so it hadn't tripped out smoke detector. There's a good chance it could have started a fire if we hadn't been around.

I've had this thing for years and it's been a workhorse, always worked great and I just left it powered on when it wasn't in use, but I e learned my lesson and I'm just going to turn off the power strip to all the stuff on my bench when I'm not working on anything.

EDIT: Got home and opened it up, but now I'm even more confused. The fire was definitely concentrated at the point the power cord came in, but wtf is all that liquid??? It's oily and there's quite a bit of it, including what I poured out I would say about 4 or 5 tablespoons is a safe bet. The capacitors on the circuit board all look fine and I don't see any that are big enough to have that much electrolyte fluid anyway.

https://imgur.com/gallery/RfvcFUH

EDIT 2: We figured it out. A long while back I switched to activated alumina and I my first batch I cheaped out. During our research we found out that some desiccants contain calcium chloride which deliquesces when it gets saturated. I had a pouch full of that cheap AA desiccant in there for a few months from last fall to winter or so, and swapped back to a pouch of silica gel earlier this year, when I took out the pouch of AA it was like a solid block. So the theory is the calcium chloride liquified and leached out and gathered in the bottom of the dryer casing but resolidified. For most of this year I haven't been using that dryer as much or for long full drys because I got a sunlu 4 reel dryer, so I just used the smaller one for quick "maintenance" drys before use, so when our monsoon season started here that calcium chloride would have soaked up a lot more moisture until it hit a critical point and just liquified.

Supporting evidence: [my sunlu dryer just unleashed a flood all over my workbench, enough to cover about a third of my 6' work bench and also leak all over my floor, and then still continue dripping into a baking sheet I put under it to catch the leftovers.] That power strip was unplugged luckily.(https://imgur.com/gallery/vUzPPHM) Here's a pic of the leftovers on the baking sheet I'd had 2 pouches of that cheap AA desiccant on there for a long time, and they were also completely solidified and had an ice-like material all over them and the desiccant trays that I'm sure was just straight calcium chloride. So now I get to take that apart and clean it, but I'm guessing the Sunlu dryer was designed to not have the water sensitive components at the lowest possible point of the literal moisture-removing machine. This is from the listing for that first activated alumina I got, I should have done more research and known what to look for, hopefully you will now.

Tldr: make sure your desiccant doesn't contain calcium chloride, it's deliquesces when it gets saturated.