i have weird problem with my led on my h2c…
as soon the ams is changing filament the lights are kind of getting dimmed for a second, there
its hard to take a pic of u hardly can see ith with ur eyes…
anybody had this before?
heres a video in the end u can see the light…
A number of Bambu printers have high current draws on the heaters. It’s worse on 240V since the current on resistive loads doubles compared with 120V.
I’d bet you’re just seeing some voltage drop as the current spikes. You might want to look at current draw and other loads on that circuit, and maybe even check connector tightness to make sure no loose wire connections are making things worse (de-energized, of course).
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i can remember a few days ago the power cord went out… when i tried to put it in it was kind of loose…
a voltage drop is what its is i think,after looking at it closer it appears exactly when the ams is rotating the spoools….. i can imagine when the printer is shaking the power cord is wiggling and maybe thats becasue got loose… i try to get another cable with a 90degree angle because mine is close to the wall…if it still flickers i will open a ticket..
Is it not related to the moment when the induction heater kicks in, that is causing quite a large power draw.
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If your lights are flickering that is usually a sign that there is too much current being drawn for the circuit to handle it. At my moms house the lights flicker when the ac compressor kicks on. I’ve tried to warn her about it saying that the electrical panel needs updating but it’s like talking to a person who denies everything and anything is ever a problem.
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Not really visible by eye, but on my H2C’s camera I can see a very short decrease in light intensity when the nozzle heater comes on.
Not surprising and not something I’d be concerned about. It’s a transient load. The power supply takes a tiny amount of time to respond to the load, and you see that as a slight/short drop in the intensity of the chamber LEDs.
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Yes, I have the same as described
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yeah thats exactly it! thats the exact moment
im not sure i dont think it has nothing to do with the circuit… im in germany electricity is pretty good in every house…since there are a lot of rules… its like the person below is saying it kind of starts to light up a lil bit when the hotendes start heating
You are misunderstanding. Not the power going to the printer. This is a behavior caused by the way an internal power supply works. The internal LED lighting dims slightly when the hot end heats up. Even if your AC power source was perfect, it would still happen because it has nothing to do with the AC power source and everything to do with the output of a power supply that draws on that source.
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ohhh sorry haha now i understand 
i haven noticed it again but if it happens again i will open a support ticket
“… It’s worse on 240V since the current on resistive loads doubles compared with 120V…”
Short answer: no.
Longer answer: The heater on the 240V model is higher resistance, so between that and the voltage being higher, less current is being drawn compared to the 120V model. The flickering is likely the consequence of Bambu connecting various loads to the same supply, so when one draws more current, it briefly “blips” the power to all loads.
Yeah. Watts = Volts * Amps. If the build platform heater is rated, say, for 240 Watts (to make the math easier), at 120V it draws 2A and at 240V it only draws 1A.
If they used the same heating element at 240V, it would draw twice the Amps as 120V. Watts would be 4x higher, 960W. It would heat up a lot faster.
But the internal power supplies have “regulated” outputs that compensate for load changes to maintain a steady output voltage, which is a requirement to ensure stable operation of all the electronics. But a power supply’s ability to respond to sudden transient changes in load is finite, there’s always a time delay. During that period, the voltage drops. It doesn’t fall far enough to cause a problem, obviously, but the LED brightness is directly related to the voltage that’s driving it. And because LEDs respond to voltage changes almost instantaneously, the flickering is apparent. If the lighting was using incandescent bulbs, it wouldn’t be as noticeable because the filaments continue to glow for a short time when power is removed.
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I don’t think that’s true on the Bambu printers though. If I remember correctly they use the same heaters on many/most/maybe all of their printers - rated for 240V. Those of us running them on 120V see half the current draw as the people on 240V.
I could be wrong though. I haven’t metered out any heaters destined for 240V locations. I’m just going by what a number of others here have said on the heaters being the same.
Look for discussions here on how fast printers heat on 240V compared to 120V. That’s the advantage of 240V with these. They heat fast because of 4x higher heating on 240V.
ok today i even got An unstable system voltage error HMS_0300-4100-0001-0001
i also read online that the older printers had mean well powersuplie the new hav cheaper ones…
i will open a ticcket because if i move the powercable in the back a lil bit the printer restarts and i also can hear electricity inside the plug…
Did you get any response? I’m seeing the same behavior on my brand-new X2D. After opening a ticket, support initially suggested it might be related to power distribution and offered a roll of PLA as compensation, noting that deeper troubleshooting could involve board replacements.
That surprised me a bit given the printer is new, so I’m trying to understand if this is something others are experiencing as well, or just a unit-specific issue.
yeah they wanted to send me a new powersupply…i told them i will wait till i get more problems..
im not really looking much at the printer, i havent noticed it again.. also can be the power cable wasnt in all the way i feel like its loose and doesnt hold like it should…
I’ve been back and forth with the support on this matter, also noticed a small scuff on one of the Z-axis rods but it’s right at the bottom. They told me that if I wanna try to fix it it may require several boards to get replaced. They also asked me to remove the back panel to double check everything, I did that and they confirmed that I should just continue to use the printer and if things are getting worse then we’ll start some actual parts replacements.
The printer otherwise works just fine so I will just continue using it as is. For the moment the issues are basically more cosmetic rather than functional.
So most of today I’ve been getting 0300-8071 234219 Enhanced Toolhead Cooling Fan Malfunction. I replaced the fan with a spare and the same issue returned. I’d hid resume and noticed the similar unit lights dimming/flickering a little bit. Now all of a sudden I’m getting The system voltage is unstable Triggering the power failure protection function. Seems the Enhanced Toolhead Cooling fan issue. Since this issue I was able to resume and hoping the print at least finishes, I’m 18 hours in so far with about 20 minutes left.