Machine and humidifier
CPAP Machine Won't Turn On: Step by Step Checks
When a CPAP machine will not power on, the cause is usually the outlet, a loose power cord or power supply connection, or a drained battery if you run on DC power. Check each link in the power chain. If the machine still shows nothing, contact your equipment provider and do not open the device.
Signs
- Black screen and no lights
- No response when you press the start or power button
- Machine works on one outlet but not another
- Machine shuts off during the night
Common causes
- No power at the outlet
- Philips lists no power at the outlet or a device that is unplugged as the first cause when nothing happens.
- Loose power cord or power supply
- Many machines use a separate power brick. The cord from the wall to the brick and from the brick to the machine both need to be seated. ResMed's AirSense 11 guide says a black screen may mean power is not connected and to make sure the plug is fully inserted.
- Battery or DC setup problem
- If you run on a battery or DC cord, the battery may need charging, or the DC cord's fuse may need replacing, according to Philips.
- Device fault
- If power is confirmed and the machine still does not start, the device or power supply may need repair.
Fixes to try, easiest first
Try a different outlet
Plug a lamp into the same outlet to test it, or move the machine to an outlet you know works. Check that a wall switch does not control the outlet.
Reseat both ends of the power cord
Unplug and firmly reconnect the cord at the wall, at the power supply brick and at the back of the machine.
Skip the power strip
Plug directly into the wall. Power strips and surge protectors can trip or fail.
Check the battery or DC cord
If you use a battery, charge it fully and check every connection. If you use a DC cord, Philips says the fuse may need to be replaced following the cord's instructions.
Let a hot machine cool down
ResMed's AirSense 11 guide says a system fault can occur if the device was left in a hot environment, and to let it cool, then disconnect and reconnect the power adapter.
Return machine and power supply together
If it still will not start, Philips advises returning both the device and power supply to your provider so they can tell which part is at fault.
Call your equipment provider for a repair or loaner. If you will be without CPAP for more than a night or two, tell your sleep doctor's office, especially if you drive for work, have heart disease, or feel very sleepy, so they can help you get a replacement quickly.
Supplies that can help
A battery pack that runs a CPAP machine without mains power, for camping, power outages or long flights.
A cord or converter that runs a CPAP from a 12 V or 24 V DC source, such as a car outlet, RV or deep cycle …
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Frequently asked questions
Why did my CPAP turn off in the middle of the night?
A power blip, a loose cord or an outage will shut it off, since a CPAP cannot store power on its own. ResMed notes that in an outage the machine simply shuts off. Some machines also stop if the mask comes off and an auto stop feature is on.
Is it safe to sleep with the mask on if the CPAP stops?
ResMed says you can still breathe room air: nasal mask users will breathe through the mouth and full face masks have an anti-asphyxia valve that opens to room air. Still, take the mask off or restart the machine if you wake up.
Can I open my CPAP to fix it?
No. ResMed and Philips both say not to open the device. Contact your provider for service.
Sources
Last reviewed October 11, 2026. How we research · Report an error