QNAP NAS Error Code 27: How to Fix It

Q: What does QNAP Error Code 27 mean?

QNAP Error Code 27 signals a power supply failure detected by the NAS hardware monitoring system. It means the internal sensors have detected that the power supply unit is not delivering stable or sufficient power to the NAS components. This is a critical alert that requires immediate attention to prevent data loss or hardware damage.

Q: Will QNAP Error Code 27 cause me to lose my data?

The error code itself does not delete your data, but the underlying power supply failure can cause sudden unexpected shutdowns. If the NAS shuts down abruptly during a write operation, data corruption on your hard drives is possible. This is why backing up data immediately when you see Error Code 27 is the most important first step.

Q: Can a faulty power cable cause QNAP Error Code 27?

Yes. A damaged, loose, or under-rated power cable can cause voltage drops that the NAS interprets as a power supply failure, triggering Error Code 27. Always start troubleshooting by inspecting and replacing the power cable before assuming the internal PSU has failed, as a cable replacement is much cheaper and easier.

Q: How do I know if my QNAP NAS has a replaceable power supply?

This depends on your QNAP model. High-end and rackmount QNAP models (such as the TS-x73U, TS-x77, and enterprise TVS series) typically feature hot-swappable or externally accessible PSU modules. Entry-level desktop NAS units often have the PSU integrated inside the chassis. Check your model's hardware user manual on the QNAP support website (support.qnap.com) to confirm whether your PSU is user-replaceable.

Q: Does QNAP Error Code 27 always mean the power supply needs to be replaced?

Not always. While the error most often points to a genuine PSU hardware fault, it can also be triggered by a faulty power cable, an unstable wall outlet, power surges, or even a firmware bug in some older QNAP firmware versions. Work through the troubleshooting steps systematically — starting with the cable and power source — before purchasing a replacement PSU.

Abstract

QNAP NAS Error Code 27 indicates a critical power supply failure, meaning your NAS unit is not receiving adequate or stable power to operate safely. This can cause your NAS to shut down unexpectedly, become unresponsive, or refuse to boot entirely, putting your stored data at serious risk. Acting quickly is essential — leaving a NAS running on a failing power supply can lead to data corruption or permanent hardware damage.