How to fix Huion tablet pen | PW100 Stylus Problems
Updated: Oct 28, 2021
If you're like me you made the mistake of buying a cheap drawing tablet. Probably a Huion. Absolutely not a Wacom. You wanted the Wacom, but didn't agree with the crazy prices of the broken in-game auction house. Maybe it was your first tablet. Maybe you only spent like $40 on it. Maybe the pen broke about two months down the line and you find out that these so called "pens" don't even contain ink and now you're wondering 'what the fuck is all this black shit smeared all over my drawing tablet?'. Oh... that's just the glove for the H640P...
Well, as long as you don't agree with the last statement you're in luck. The very same luck you're probably realizing you're running out of after contacting Huion support about your "pen" and either receiving their automated or personalized fuck off response email. No worries. Just find your [wife's/sister's/grandma's/cousin's] nail polish remover and get ready for a wild high.
Several drips of acetone (nail polish remover)
Flathead electronics screwdriver
Solder and soldering iron (Optional, may not be required)
Perception: 8 (we're going to be dealing with choking-hazard and smaller parts so be sure to put your two year old in the kennel before proceeding)*
Only whence thee possess thou required items and passed thy skill check shall one proceed.
Okay then. Skill checks passed. Continuing.
*don't put your two year old anything in a kennel
This is my stylus. There are many like it but this one is mine.
Now get your pen/stylus/piece of Huion shit that breaks every few months out, set it down, and grab your screw driver. Yeah... Time for sweet revenge. Gently slide it in between the pen and button end.
While applying a slight twisting pressure, move the screwdriver towards the center of the button. Oh snap.
You either snapped it or it snapped out of place. Either way, good job.
Next pull the rubber inwards as seen below. The tip side doesn't need to come up at this point but I found it was easier for it to hold shape when I pulled both sides.
Now for the acetone bath.
Well... more like a drop or two to loosen the adhesive holding the upper part of the pen to the lower guts. Don't bathe it. Use an eyedropper or something to get just a few drops in the cracks, like you're oiling the tin man from Wizard of Oz.
After you do that, give it about 5 seconds and a little tug/twist and the top should pop right off. Or maybe my pen was just more of a piece of shit than usual? Either way it played out in my favor.
Now, or earlier, or any time really... is as good as a time as ever to remove the nib. Almost forgot about that, ngl.
Now removal of the rubber grip is much simpler and easy going, just grab it and slide towards the top of the pen. You can even remove it without stretching or damaging it now! Wow! Imagine that.
Meow here is where they try to get you. You would think that nice tabby thingy on the right would probably just unclick like a normal tabby thingy. Roll that bad boy over on its back and prepare to be amazed.
A snappy locky button thingy with a phantom snappy locky button circly looking thingy to the left of it. Ignore the phantom circle, we want the right one.
Using your flat head screw driver or another slim but sturdy enough device such as a paperclip or the crystalline pride of your defeated enemies press the button inward and away from the writing/nib part of the pen.
Your stylus should look similar to my stylus now. If not, order a new pen from amazon and begin again from step 1.
You might want to be delicate for this next part if you don't have a solder or aren't good with one or don't have a good one or all of the above. With the circle clip unlocked the chip simply slides out the top of the pen, looking something like...
This. Minus the nib. I kind of used blogger magic to put that part in a bit earlier where it kind of belonged.
Take note of how many exposed threads are between the blue cylinder and the black bracket it screws into. This will make reassembly/tuning much easier. I recommend taking a picture, but at a better angle than the one above.
And from here we can identify our first possible point of failure. Can you see it?
Make sure these wires are good and soldered right. Now, I'm fairly certain I more or less tore these bitches out by not removing the button from the pen before removing the chip, but hey, you live, you learn, then you learn to solder. Also make sure the wire insulator isn't damaged to the point the wires are touching. That would be a no bueno.
Take note of any damage for now, because we're not done with disassembly just yet.
Next we're going to remove the chip from the holding bracket. To accomplish this simply apply a linear thrust at a positive vector angle and multiply your rotational velocity by sigma alpha pi.
Just kind of pull back on the black tab while lifting on the chip. If you or it wants to be a dick about it you could use the screw driver I guess. Be careful though, the wires are attached to the blue cylinder, which is screwed into the plastic chip bracket. Its easy to put undue stress on the solder connections if you're not paying attention.
You're going to want to be delicate with this next part. You need to unscrew the blue cylinder from the black chip bracket without ripping out the wires from the circuit. What I found to be the easiest was to let the chip rest on the table while I unscrew the holding bracket from the blue cylinder.
BE EXTREMELY CAREFUL - VERY SMALL SPRING AND SILICON BUTTON THING CAN AND WILL FALL OUT WHEN CYLINDER IS UNSCREWED.
And its here we find our primary culprit.
This bullshit tomfuckery is the cause of all of your woes and probably more. What you're looking at now is a 'fixed' spring/button assembly. What seems to happen is that the spring gets pressed into/over the silicon "button" in such a way that it no longer does its job, which has some vital role in pressure sensing. This causes intermittent and then eventually total touch detection failure. When removing the spring from the silicon button, be careful not to stretch or bend it any more than necessary.
Pictured above is the fully disassembled cylinder ...assembly. In correct order and positioning, for reference. I'd love to know what material the center core cylinder is made out of- if you know leave a comment or hit me up on twitter @_dtgames
Yeah... that micro spring and little dot of silicon is what you're spending $30 to replace every time you buy a new one of these things...
The fix is just a total disassemble and reassembly. I ended up having to slightly modify my spring to get the pressure sensitivity just right, but that was because I had already modified the spring as part of trying to figure out the problem and repair the issue... After resolving the pressed-in spring issue, I immediately had touch sensitivity again.
Put everything back together in reverse order... but here's the tough part.
When reattaching the chip bracket to the blue cylinder you want to make sure a jib passes the "wiggle" test. You know, that cheap clicky sound the pen makes when you shake it around and the jib moves. If you over tighten the cylinder this will occur, and if you reassemble the pen incorrectly this will occur. If you took a picture or at least took note of how many threads you had exposed before disassembly you know where you should be at with that normal wiggle, and any additional tightening rotations should grip" the jib. If you get it back together, the cylinder is screwed in the correct amount, and the jib doesn't jiggle- try backing it off a bit. You should have about a 1/2 - 3/4 turn in either direction for adjustment.
Once this is done I recommend pulling up the Huion Pen Tablet app, going into the Digital Pen area, and testing your newly fixed pen. If the sensitivity seems off try adjusting the blue cylinder a bit in or out as much as your wires will let you. If all else fails a bit of spring modification should do the trick... but that's going to be some trial and error on your part. You can always make software adjustments but I personally would save that for a last ditch effort.
Oh, and if you ripped those wires or they were ripped on disassembly now would probably be a good time to re-solder those.
Notes on reassembly:
The tapered end of the silicon button should face the spring (away from the center of the blue cylinder), so that the tapered end of the spring sets into it.
The tapered end of the spring should face into the blue cylinder. If the spring is positioned incorrectly the pen will not function.
Align the circle button to its snap-in placement before sliding the chip bracket back into the pen shell.