inside a zmuipng usb c 18-port docking station

So if you’ve wondered what’s inside of one of those 18-port USB-C breakout interface boxes that exist under various brand names – this one being a zmuipng which is popular somehow – I have photos for you! And an assortment of notes, so this is kind of a teardown.

First, opening the box: remove the two long rubber feet by peeling them away. This will reveal two screw recesses, one under each foot. Remove the screws.

This will let you spudger the top off starting on the short sides. Lever them up alternately and it’ll come clear without too much of a fight, but be very careful about the headphone jack! It’s fragile. I broke off a bit of plastic taking this one out.

The idea solution would be to spudger out the bottom, but on my unit, that was glued in. I’m fairly convinced the assembly procedure involves installing the top board, then screwing down the daughterboard that holds the screw headphone jack (and connecting the cables), then inserting the glued (!goddammit!) bottom board, screwing it all into place, and adding the feet.

Anyway, here’s the chip side of the upper board:

The big chip is an RMC RTD2183 [closeup]

I didn’t do much with the upper board; none of the chips on it seemed to gain much in the way of temperature and there’s no obvious signs of damage. The big gold ribbons go to the lower board; the smaller white ribbon goes to a headphone jack daughterboard, which connects to the two metal posts you can see in the upper left. That’s the one you have to be careful about.

And the bottom board:

Look at all this stuff! [closeup 1, closeup 2]

There are two of VLI VL103R-Q4, another crab logo chip, this one an RMC RTS5411S, a VLI VL817-Q7, and an L172 and an L171 and I have no idea what those are but you can look at the closeups.

But more importantly, the reason I opened this thing is because Anna is having trouble with it blanking all its displays on and off, and from the way it’s doing it, it seems to be sending confusing signals to her laptop after running for a while. And that to me smells like heat. So I poked around for a bit and here are the chips getting hottest:

Particularly the one on the right, I think

The left one – the smaller one – is definitely showing up running a good 10°C hotter than most of the board. The bigger one isn’t showing up hotter at all with my laser thermometer, but it sure does evaporate isopropyl quickly! And also feels hot. So I think my laser is getting confused by the big HDMI grounding shield. It doesn’t like reflective stuff.

I ended up adding four heat sinks, which is maybe more than I needed, but I thought I’d hit the four warmest chips. It’s the two up there that were most obvious though.

yep, them’s heatsinks.

The question, of course, is WILL IT DISPERSE?

And well yeah I can feel it, they’re definitely dispersing heat. But what I don’t know is if this actually fixes anything xD

I considered adding a pair of venting holes, one on each of the short sides .There’s plenty of clearance space for such things. But I’ve decided against it for now, particularly given that it’s drilling through metal and plastic and I don’t even know if this is the problem.

BUT FOR FUTURE REFERENCE

The safe drilling band at front-to-back centre of sides starts 30mm from the top and ends 42mm from the top. So centre a drill bit at 36mm down and use an 8mm drill bit for a safety margin. Also, use a drill stop of 5mm depth to avoid hitting the case screw support columns. That should be safe.

So yeah. I went looking for “how to take apart stupid USB brick” and got nothing, so maybe someone will be able to find it now. I talked about it live on Mastodon if you want to read that and see all the photos in original order for some reason. But it’s all copied over here.

If it turns out this makes the problem go away, I’ll update this post. She’s not the only person who’s seen it.

Posted via Solarbird{y|z|yz}, Collected.