Since we normies don’t get access to the schematics so hard to tell. Definitely significantly harder than just plugging in a fan though. You’d have to find out where it is, measure it, source a replacement and solder it in. I have done that on a think-pad but I was able to source the schematic for that (well I didn’t replace it per se but it counts XD).
If something blew it also may not necessarily be the fuse but could also be something downstream from it.
Let’s hope it’s just the fan and it didn’t damage anything else. Since the laptop otherwise run the ec is probably not entirely destroyed but there is a non 0 chance that the fan signal pins are damaged. That would be extremely un-fun.
Edit: @Proton1 Out of curiosity could we get a few more close up pictures of the fan hub from different angles? Even better if you could get rid off the rest of the label.
My 2cents:
In this computer the fan speed doesn’t have closed loop feedback, the temperature only controls the fan PWM duty cycle. The four wires of the fan are power source, PWM signal, RPM reading and ground. If I remember correctly, of you plug a fan directly to a power source (only connect power and ground) the fan will run full speed. If a signal wire broke, upon replacing the fan you either get full speed, or unable do get the RPM reading. A fan motor like this may or may not have a controller, a simplest BLDC fan only has a few hall effect sensors and transistors to use the spinning magnet to do the commutation instead of using brushes and the PWM signal comes form the computer.
For pc fans that is indeed specified, no pwm singal means fully on. Pwm low is a bit is a bit more inconsistent, some fans take that as off and other as some form of min.
Here however we got a lapop fan, those are a lot less standardized. I do agree though that in the case of a missing signal you’ll likely get off or full bore. However more likely than the signal being missing is it being shorted to ground which would almost certainly mean off. Missing rpm reading would be less bad. Usually there should be resistors on the pwm and tach lines so the ec is hopefully fine.
You are giving those controllers too little credit, they may only have very few pins but they do the entire thing themselves, the pwm signal from the computer is just the desired speed dial and is not involved in the actual driving of the motor. I have not seen a brushless dc fan (at least computing related) without a controller before. If I didn’t know any better I would have mistaken the controllers on some fans as just being a hall sensor.
I think that depends on make and models. On one of BLDC cooling fans(a 12V 1.6A desktop computer cooling fan) that I own I’m able to adjust the speed by adjusting the input voltage (signal pin disconnected) or PWM the input power(not signal). If the fan has a controller there’s a minimum working voltage for the controller, adjusting the input voltage might not work.
No you can pwm the controllers, we do that all the time on 3d printers, it’s barbaric but it totally works.
No thanks to inductance in the motor (and parasitic capacitance and other magic ac fuckery) the actual voltage at the controller doesn’t usually drop to 0 and even when it does those controllers start fast. Adjusting the input voltage also doesn’t work down to 0.
Seriously those things are nice little fully integrated, sensored, single phase ac motor drivers.
The fan is not available separately from Framework. I imagine there must be a way to get the fan off, but it seems it’s a bit involved. A member posted steps to open the fan casing to clean it (or replace the important half I guess) but didn’t see how to completely remove it.
Is it fine leaving the keyboard hole unpatched? I’m worried about taping it up as if this happens again, the tape adhesive might melt and gunk up everything.
Thanks a lot for satisfying (at least some of) my curiosity.
I would reccomend against that. It is an open hole into something that looks like it’s supposed to stay inside. But if you use kapton/polyamide tape you don’t have to worry about it gunking stuff up in the unlikely case it happens again, that stuff wll start to break down long after all the other plastics in the keyboard are a liquid or worse XD.
Looking at the pictures I guess I blamed the controller prematurely, that thing is just sitting there unscathed (it may still be dead but it at least doesn’t look like it got anywhere near as hot as the bit where the cables are), maybe the bypass capacitor failed short? There are usually not that many other components on a fan other than the controller and it’s cap. The cirquitboard just failing short sounds unlikely.
Thanks for the great photos. Nothing wrong leaving the hole unpatched. It is sealed up in the laptop normally. If you have a little Xacto knife you could carefully cut away the damaged around the hole.
Maybe stick part of a popsicle stick in the hole as you cut so you don’t cut into the backside of the keyboard. If you had some really small scissors or even a pair of nail clippers you could do a little plastic surgery little by little to clean it up cosmetically.
Hope your replacement fan/heatsink arrives soon. Thanks for the update.
peeling off the sticker requires significant force. I don’t want to damage the fan. Anyway here’s what near the wire. Here are P - F +, which probably means PWM, GND, frequently, voltage source
Seems to match the color coding, blue tends to be pwm and yellow tach, red and black probably don’t need much thinking.
But this isn’t the same fan as the order of the wires is different. On the burned one it’s blue, red, yellow, black.
According to the controllers datasheet it needs 2 capacitors, 1 small one close t the controller and a bigger one to temporarily store the power coming back from the coils, if that one was in that area it would probably be it. That capacitor is probably the thing with the most stress on it on that whole board.
Asking proton to autopsy the fan is probably asking too much here XD.
I just had the same failure on my first gen (i5-1135G7) Framework.
I’m just minding my own business, soldering together a weird keyboard at my computer desk…I hear a clicking noise from my right, which is weird because there shouldn’t be anything over there making noise. I look up and there’s smoke – for a moment, I think “is that from my soldering iron?” but then I realize it’s way too much smoke and it’s in the wrong place!
My next thought is that I’ve got a lithium battery fire on my hands, so I run around my desk, unplug the laptop from the dock, and run down the steps and out the front gate in my socks. I notice during this process that the laptop does not seem to be actively on fire…eventually I am able to get my tools and unscrew the bottom of the laptop. I open up the computer to lift off the input cover and find the computer is still on! Good indication that the battery has not failed.
The damage is not immediately obvious, but I eventually notice the burn marks on the fan.
Phew, that freaked me out. I think I caught it much earlier than u/proton1, because there’s much less damage.
That’s a little worryingly to me. I thought my fan failure might just be a one-off issue. But from the photos it does seem that we experienced the exact same problem, with mine unfortunately having a longer exposure.
Did replacing the heatsink and fan resolved your issue?
That is eerily in the same location as the other one, I wish I knew what’s under there.
Could be the big cap for the motor driver but it’s hard to tell, very unlikely that it’s just a random bit of the pcb that decided to blow itself up in the same spot on 2 fans.
I am assuming in your case the motor driver still looks fine and there isn’t any discoloration near it right?
Since the fans are dead anyway can one of you autopsy one? Would love to see that pcb without the plastic.
The failure happened just an hour before my post, so I haven’t had a chance to repair yet. I don’t anticipate it being a problem given the laptop was still functioning partway through disassembly. Might take the opportunity to switch to PTM7950, hopefully this will resolve some of the excessive fan noise I’ve been having.
I don’t expect Framework to revise this component so far after the production date, there’s just no way that’ll make sense economically. I might disassemble the fan out of curiosity, though.
Replacing the HSF was as easy as replacing a desktop HSF. Easier even, since I didn’t have to apply paste myself (didn’t bother with PTM7950). I’m impressed.
I partially disassembled the HSF, but I can’t find a good way to separate the shroud from the controller PCB. I’m not planning to investigate further, but if someone wants the failed fan I’m willing to ship it.
Glad to hear replacing the component went smooth and easily. If there was more widespread failures like this it would be worthy of looking further. Such a simple mechanism and relatively inexpensive to replace.
