Replacing a failed power supply in a Ubiquiti UniFi US-16-150W switch isn’t something most people plan to do — but when the switch is out of warranty, sometimes you either try to fix it or write it off completely.
In this project, I decided to attempt a power supply replacement, document the process, and see whether the switch could be brought back to life.
It did work… briefly.
And then it all went wrong.
If you’d prefer to watch the full repair attempt, including everything that went right — and wrong — you can check out the video here.
Jump to the Section You Need
- ⚠️ Important Disclaimer
- Why the UniFi US-16-150W Power Supply Fails
- The Goal of This Project
- Choosing a Replacement Power Supply
- The Power Supply Replacement Process
- Powering Up and Testing
- When Disaster Struck
- What Went Wrong (Lessons Learned)
- Video Walkthrough
- Looking for Ideas (Your Help)
- Useful Tools Mentioned
- More UniFi Guides & Real-World Fixes
- Final Thoughts
⚠️ Important Disclaimer
I’m not an electrician, and this was very much a learning-as-I-go project carried out on my own equipment.
Working with power supplies and mains voltage can be dangerous.
If you’re not confident or qualified, do not attempt this yourself.
This article is for educational purposes only.
Why the UniFi US-16-150W Power Supply Fails
The US-16-150W is a popular UniFi switch, but like many compact PoE switches it runs:
- Warm
- Under constant load
- Often 24/7
Over time, the internal PSU can fail due to:
- Heat
- Component ageing
- PoE load stress
When this happens, the switch usually becomes completely dead.
The Goal of This Project
The aim was simple:
- Remove the failed internal PSU
- Fit a compatible replacement power supply
- Power the switch back on
- Re-adopt it into the UniFi Controller
If successful, this would extend the life of otherwise scrap hardware.
Choosing a Replacement Power Supply
Finding a suitable replacement power supply took a bit of research. There were several similar-looking models available, so I spent some time checking the specifications to make sure the output ratings matched what the switch required.
Once I was confident the electrical specifications were correct, I ordered a replacement PSU from Amazon. At around £20, it was very reasonably priced and made the repair attempt worthwhile compared to replacing the entire switch.
👉 (Amazon affiliate link to the replacement PSU)
As an Amazon Associate, we earn from qualifying purchases. Using these links helps support the channel and allows us to keep producing real-world UniFi guides and videos.
While this was a non-OEM replacement, the specifications appeared suitable and it powered the switch up without issue during testing. As with any third-party PSU, it’s important to double-check ratings and fitment before ordering.
The Power Supply Replacement Process
The first step was to remove the switch casing by unscrewing the case screws and sliding the cover off, giving access to the internal components.
With the internals exposed, I disconnected the original power supply from the main board and unscrewed it from the chassis, allowing it to be removed completely.
Once the old PSU was out, I placed the replacement unit into position inside the chassis to check clearances and cable routing.
Before carrying out any wiring, I made sure the power cable was fully unplugged from the mains. I then cut the existing power cables to length and used a crimping kit to strip the insulation and properly terminate the cables.
Using the crimp terminals from the kit, I crimped the cable ends and securely fastened them into the replacement PSU’s input terminals. With the cables correctly terminated and secured, the PSU was electrically ready to be powered up.
The entire process was straightforward and didn’t take long to complete. With the right tools, terminating the cables was simple and resulted in a clean, secure connection.
👉 (Link to the crimping kit used on Amazon)
Powering Up and Testing
With the replacement power supply installed and wired, I powered the switch back on.
The front LED illuminated immediately, and within a few seconds the port LEDs began to light up, indicating that the switch had successfully booted and was ready to go.
To start clean, I performed a factory reset on the switch before reconnecting it to the network. Once reset, I plugged it into my main switch in the cabinet and instantly achieved a network link.
Checking the UniFi app, the switch appeared straight away and was ready for adoption. I adopted it into the UniFi Controller without issue, confirming that the PSU replacement had been successful.
At this point, the switch was fully operational — success.
When Disaster Struck
Just seconds after adopting the switch into the UniFi Controller, everything went wrong.
As I turned in my chair, I caught the patch lead connected to the switch, pulling it off the bench and onto the floor. Because the replacement PSU wasn’t fixed in place, the movement pulled the mains connections loose, causing the cables to arc against the PSU.
There was a big spark, the house power tripped, and the replacement PSU was instantly dead.
After finally getting the switch working again, I was suddenly back at square one.
I’ll be ordering another PSU and attempting the repair again soon — but next time, the mechanical mounting will be sorted properly before power is applied.Painful — but also a valuable lesson.
What Went Wrong (Lessons Learned)
Electrically, the repair itself went well. The replacement power supply was correctly wired, the switch powered on, and it operated normally once adopted into the UniFi Controller.
The failure occurred because the replacement PSU had not yet been mechanically fixed in place. When the switch was accidentally pulled off the bench, the weight of the loose PSU caused strain on the power cables, pulling them out of their connections.
As the cables came free, they briefly arced against the PSU, resulting in a large spark, tripping the house power and destroying the replacement power supply.
Had the PSU been properly secured to the chassis, it’s very likely the switch would have survived the fall without issue. The incident highlighted that mechanical mounting and strain relief are just as important as correct electrical wiring, even during testing.
Video Walkthrough
I documented the entire process — including the failure — in the video below:
Looking for Ideas (Your Help)
This is where I’d really appreciate some input.
The electrical side of the repair worked fine, but I still need a proper mechanical mounting solution for the replacement PSU. I did consider 3D-printing a bracket, however there are some constraints — the replacement PSU is larger than the original, and the existing raised screw mounts inside the case limit the available height, which makes designing a printed bracket tricky.
If you’ve:
- Replaced a PSU inside a UniFi switch
- Designed a compact mounting solution in a tight chassis
- Used brackets, plates, or even an external PSU approach
Please add your ideas in the comments below. I’m genuinely interested in how others would solve this, and I’ll be testing suggestions and publishing a follow-up once the switch is properly fixed.
Useful Tools Mentioned
Links to some of the tools and parts used during this project:
As an Amazon Associate I earn from qualifying purchases. These links help support future content.
More UniFi Guides & Real-World Fixes
This project is part of a growing collection of real-world UniFi guides covering:
- Networking
- UniFi Protect
- Switches
- Cameras
- Troubleshooting
You can find more here:
👉 https://knowledgehub.hns-berks.co.uk
Final Thoughts
This wasn’t a perfect success story — and that’s exactly why it’s worth sharing.
Not every repair goes to plan, but every one teaches something useful.
With a better mounting solution, this UniFi switch will almost certainly live to fight another day.
Author: Huw Jones – Home Network Solutions Berkshire
Huw is a UniFi specialist and the owner of Home Network Solutions Berkshire, providing professional networking, CCTV, gate automation and smart home installations across the UK. With years of hands-on experience and a growing YouTube audience at @home.network.solutions, Huw creates practical, no-nonsense guides to help homeowners and installers get the best out of their UniFi systems.
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