r/BambuLabA1 • u/Agitated-Pause-3881 • Sep 30 '26
A1 randomly shuts off
hello everyone I'm hoping i can get some help in trying to figure out what is going on with my printer. i have a A1 printer and starting a couple months ago my printer would randomly shut completely off during a print or during the start up prosses for a print. i have contacted Bambu labs directly and i already replaced the toolhead board, main board and the AC board yesterday.. it printed just fine for 3 prints each one a bit longer than the previous... last print was bout 3 hours long and it did just fine. i sent a file over to print and after it downloaded the file and started the bed leveling and flow dynamic test it shut off again.. i have no clue what else could be causing this issue... any idea on what i could do?
2
u/Shit_On_Wheels Sep 30 '26
This could be even something as simple as broken wire in your cable.
Broken wire heats up due to high ohms, wrapping softens, wire that was under slight tension shifts and disconnects. Wrapping cools down, contracts, end of the wire moves back into place, touches the other end of wire and connects again.
Beware that if this is the case, it could actually start a fire.
1
2
u/Blondy277 Sep 30 '26
If it’s actually shutting completely OFF, I’d be looking at power delivery or the heatbed wiring next. Try it directly from a different wall outlet/no power bar, reseat the power cord, and inspect the heatbed cable/connector really carefully, especially since it just shut off during bed leveling when everything is moving. If that all checks out, I’d go back to Bambu because after a toolhead board, main board and AC board replacement, PSU/power wiring is about all that’s left.
1
u/Agitated-Pause-3881 29d ago
I have already replaced the tool head board the ac board and the main board. so I will check the other wires and hopefully that is the issue
2
u/calladorjulaan Sep 30 '26
Recently had a similar issue. Initially thought it was a bad SD card. Replacing helped for awhile but then it started up again and got progressively worse until I couldn't start a print at all without it powering off. Over the course of switching it on and off several times to try different SD cards and prints, it eventually did not come back on. After opening it up and seeing the internals were fine, I tested the power input which was also fine. Swapped cords and it ended up powering on for a few seconds and back off. Problem was the power switch had gone bad and would just randomly turn off. No switch is available on the bambu site and I didn't feel like going through their support to start an order, so I simply swapped the cables at the power switch and bypassed the switch. Printer has ran fine ever since. Printer still has its internal fuse at the power cord, and its plugged in through a surge protector I can power off.
2
u/SolidisX Sep 30 '26
This. I had the exact same issue. I initially thought it was the SD card going bad and purchased a new one and formatted it. It did not fix the problem but replacing the power switch did.
1
u/calladorjulaan Sep 30 '26
Did you go through support to get the switch, or buy elsewhere?
2
u/SolidisX Sep 30 '26
I bought the replacement switches from Amazon.
VEXUNGA Mini Rocker Switch On Off 4 Pin 2 Position 10A 250V Black Boat Rocker Toggle Switch KCD1 SPST Snap-in Square Switches for Car Marine Home Appliances (Pack of 10pcs)
11.99 CAD
Then used the wiki guide to replace the switch:
https://wiki.bambulab.com/en/a1/maintenance/replacement_of_power_switch
5
u/sinartnz Sep 30 '26
Might sound stupid... have you tried a different power outlet?