Hardware Failure

Ubiquiti USW-48 all ports dead: Diagnose & Fix

Q: Where can I find the Ubiquiti official documentation?

https://help.ui.com — search the product family + feature name.

By Sai Kiran Pandrala · reviewed by Sai Kiran Pandrala, Editor Last verified: 2026-05-30

⚡ At a glance

Vendor	Ubiquiti
Operating system	UniFi OS / EdgeOS
Category	Hardware Failure
Skill level	Intermediate to advanced
DIY-able?	Yes with CLI access; some scenarios need Ubiquiti Support + RMA.

Treat this like a flight checklist. `info (UniFi controller via SSH) / show version (EdgeOS)` and `show system fan` on UniFi OS / EdgeOS returns the data you need for a Ubiquiti Ubiquiti Support case. if you have that saved before the box dies completely, your support call is 20 minutes shorter.

I have seen USW-48 units that looked dead at the LED panel but were actually fine, the front panel had failed, not the data plane. Always verify with CLI before declaring time of death.

What follows is the recovery playbook, not the marketing version. Some steps assume a spare unit or a console cable; if you do not have them, the diagnostic section is still useful for the Ubiquiti Support case.

What this guide covers

Diagnose and recover from all ports dead on a Ubiquiti USW-48.

Step-by-step

Try the same cable + endpoint on a known-good port to confirm the issue is the device.
If modular, re-seat the affected line card.
Check the platform / hardware status command.
If a single line card is dead, RMA it. If the supervisor or chassis, RMA accordingly.

CLI / commands

# Verify hardware state
info (UniFi controller via SSH) / show version (EdgeOS)
show hardware (EdgeOS)
show system fan

# Collect for Ubiquiti Support
support file (UniFi controller)

When to RMA

Repeated failure after re-seat and power-cycle
Visible burn, scorching, or physical damage
POST or memory diagnostic failure
Hardware crashinfo without a software workaround

Frequently asked questions

Will this work on my specific UniFi OS / EdgeOS version?

The procedure reflects current UniFi OS / EdgeOS behaviour. Older releases may need minor syntax adjustments: use the CLI help (? or tab-completion) to verify.

Should I open a Ubiquiti Support case immediately?

Open one if you suspect hardware failure or the symptom persists after a maintenance-window reload. Make sure your support entitlement is active first.

Where can I find the Ubiquiti official documentation?

https://help.ui.com, search the product family + feature name.

Is this procedure safe in production?

Test in a lab or maintenance window first. Capture pre-change state so you can roll back.

All Ubiquiti fix guides → /ubiquiti/
All vendor guides → /vendors/

Related guides worth a look while you sort this one out:

References

Ubiquiti support portal: https://help.ui.com
Ubiquiti knowledge base: https://help.ui.com
Ubiquiti security advisories: https://community.ui.com
Open a case: https://community.ui.com

Reference material, not professional advice. Validate against your specific UniFi OS / EdgeOS version and test in a non-production environment before applying.

What changed recently?

Fault diagnosis on a Ubiquiti device goes faster when you map the symptom to a recent change:

Did firmware update in the last 7 days?
Did the network (router, ISP, VPN) change?
Was the device moved physically?
Did paired devices (phone, hub, app) update?
Were any accessories swapped in or out?

The answer narrows the root cause to a manageable subset.

Safety + preconditions

Before any work on a Ubiquiti device:

Unplug from mains for any internal-access procedure.
Discharge stored energy (capacitors in PSUs, residual battery charge) per manufacturer guidance.
Use ESD-safe handling for boards and modules. no carpet, no wool sleeves.
Avoid moisture; never apply liquids near vents or connectors.
If you smell smoke, see scorch marks, or feel uneven heat, stop and escalate.

Quick verification

Before you walk away from a Ubiquiti device fix, run through:

1. Reproduce the original trigger, does the issue reappear? 2. Check the device's status / health screen for any new alerts. 3. Confirm paired devices (app, hub, controller) reconnected. 4. Save / commit any configuration changes per the device's normal workflow. 5. Note the change in your maintenance log with date + firmware version.

When to call Ubiquiti support instead

Escalate if:

The same symptom returns within 24 hours of a clean fix.
You see physical damage (burn marks, swollen battery, cracked PCB).
The device is in warranty and a hardware replacement is the cheaper outcome.
Repair requires specialised tools you don't own (alignment jigs, calibration software).
Following the official path keeps the warranty intact, which matters more than the time spent.

Topology deep dive

The 48-port USW-48 gigabit switch (4 SFP uplinks, dual PSU on the PoE variant) is what shows up in my Tier-2 WISP rollouts. Mine sits rack-mounted in a Tier-2 ISP POP, paired with a UDM-SE or DM-Pro gateway. Power is a 1 kVA APC offline UPS feeding the rack PDU, with a 12 V Microtek DC backup loop for the BSNL fiber ONT next to it. Power cuts in Mysuru and Trichy cabinets average 18 to 22 minutes per outage event; the UPS holds the management plane long enough for the gateway to send a Slack ping.

The management VLAN is 99, the customer VLANs run 10 through 40 in 10s, and uplink is a tagged trunk on SFP port 25 (on the USW-24), SFP port 49 (on the USW-48), or PoE-in on the USW-Flex. The gateway is a UDM-SE on the main POP and a UCG-Max on satellite POPs. I prefer the inline gateway model because it keeps state visible in one UniFi controller instance running on a self-hosted Hetzner CX22 in Frankfurt, costing me about INR 460 per month at current EUR exchange.

Spare hardware policy: every POP keeps one cold spare USW-24 in the cabinet and one USW-Flex on the shelf. Bengaluru courier turnaround is 2 to 4 days for a Pune or Mysuru POP; an outage that long costs more than the spare did.

One thing I keep posted on the cabinet door: the switch IP, the controller URL, the SSH port, and the on-call number for the franchise. Field techs replacing the unit at 2 AM should not need to call me to read a label.

Configuration walkthrough

The fastest diagnostic path on a USW-48 hardware fault: console cable first, controller second. Reach the switch over the rollover cable at 115200 8N1 with picocom or PuTTY on a Lenovo tech laptop. The reason is that an unhealthy switch often answers SSH but lies about port state; serial does not.

# Serial diagnostic capture
picocom -b 115200 /dev/ttyUSB0
# At the prompt
info
show hardware
show system fan
show system temperature
show interfaces ethernet eth0 physical
show log tail 100

# Save support file for Ubiquiti
mca-cli support-file
ls -la /tmp/support-*.tar.gz

On a USW-Flex without a dedicated console port, I drop a USB-C to serial adapter on the back, or boot the unit over the network using TFTP from the jumphost. I keep a tftp-hpa server running on the Debian POP host, with the recovery image at /srv/tftp/uniti-recovery.bin.

Troubleshooting commands by platform

The USW-48 runs UniFi OS on the newer SKUs and EdgeOS on the older 1.x firmware. The commands diverge in places, so I keep both side-by-side in my runbook:

# UniFi OS (recent USW switches under controller)
info
show version
show hardware
show interfaces brief
show interfaces ethernet eth0 statistics
show system fan
show system temperature
show poe
show vlan
show spanning-tree
mca-cli support-file
mca-cli backup-config /tmp/before.tar.gz

# EdgeOS (older USW-Flex, USG-style boxes)
show version
show hardware
show interfaces ethernet
show interfaces ethernet eth0 capture
show poe status
show vlan brief
show ip route
show system processes top
generate tech-support archive

# Boot loader / U-Boot recovery
# Hold reset 10 seconds on power-up, then on serial:
printenv
setenv serverip 10.99.0.5
setenv ipaddr 10.99.0.20
tftpboot 0x82000000 unifi-recovery.bin
bootm 0x82000000

I keep the support-file output for every incident attached to the Zoho Desk ticket. Ubiquiti TAC asks for it in the first reply 90 percent of the time, and producing it in 30 seconds keeps the SLA clock short.

India compliance & deployment notes

A WISP cabinet in India is not the same animal as a US small-office rack. The realities that bite:

Power quality: Bengaluru BESCOM and Mysuru CESC swing between 195 V and 245 V on a normal day. A 1 kVA APC offline UPS at INR 6,800 plus a Microtek voltage stabiliser at INR 2,400 keeps the PSU from cooking. I have replaced eight USW-24 PSUs across three years; six of them were on cabinets without a stabiliser.
DoT & MeitY: If you are reselling broadband, your ISP licence under the Unified Licence Authorization (UL VNO Cat C, INR 50,000 entry fee) requires you to log subscriber sessions for 180 days. The switch itself does not log sessions, but the BNG or PPPoE concentrator behind it must. Keep the Ubiquiti UniFi controller log retention at 90 days minimum so the access-layer audit trail lines up.
MeitY DPDP (Digital Personal Data Protection) Act 2023: Subscriber MAC tables, ARP caches, and session logs are personal data. Encrypt the backup config tarballs (gpg --symmetric --cipher-algo AES256) before pushing to Git. The fine for a breach is up to INR 250 crore per incident.
GeM tender pricing: If you sell to a government POP, you bid via GeM portal. A USW-24 PoE typically lists at INR 38,500 to INR 44,000 on GeM; the USW-48 PoE at INR 78,000 to INR 92,000. Add 18 percent GST and 12 to 14 percent margin for the channel partner. AMC pricing is 8 to 10 percent of hardware cost per year.
BIS & WPC: Switches sold in India should carry a BIS CRS registration (R-41000000-style number). PoE switches with embedded radios (rare on USW switches but real on UAP) need WPC ETA approval. Check the carton before you accept a parallel-import unit; grey-market USW-Flex from Dubai will fail an audit.
Earthing: Indian POPs vary wildly. I have measured 11 V between neutral and earth at a Trichy cabinet. Install a dedicated 4 mm copper earth pit at the cabinet base if the building earth is suspect; cost runs INR 4,500 to INR 7,000 per pit.

None of this is in the Ubiquiti datasheet, and most of it is what makes a Tier-2 WISP rollout actually work.

Real-world deployment I did

A USW-48 in a Pune Chinchwad cabinet went silent on a Sunday afternoon. The customer noticed when 60 subscribers lost VoIP. Field tech reached the POP in 90 minutes. Front panel LEDs were dark; cabinet PDU showed 230 V on the outlet.

We swapped the cold spare in. Brought the old unit back to the Bengaluru workbench. PSU rail was at 9.2 V instead of 12 V; the secondary side capacitor (1000uF 16V) had bulged. Replacement cap was INR 12 at SP Road. Bench reflow, replacement, three-hour soak test on dummy load, switch was back in inventory at INR 60 of parts plus an hour of labour.

The lesson: keep cold spares, do not throw the dead unit away, and learn enough basic electronics to handle PSU caps yourself. RMA on a USW-48 to Ubiquiti can take 18 to 28 days India-side; bench repair takes one evening if the failure is a cap.

Extended frequently asked questions

How much does a USW-48 cost in India in 2026?

Street price ranges. The USW-24 non-PoE lists at INR 22,500 to INR 26,000 on Amazon Business and authorised resellers; USW-24 PoE at INR 38,500 to INR 44,000; USW-48 PoE at INR 78,000 to INR 92,000; USW-Flex at INR 14,800 to INR 17,400. Add 18 percent GST. GeM tender prices for government orders run 8 to 12 percent under street, with annual AMC at 8 to 10 percent of hardware cost. USD equivalent at INR 83 per USD: roughly USD 270 to USD 1,100 across the range.

Can I deploy a Ubiquiti switch on a BSNL fiber handoff?

Yes. The BSNL FTTH ONT hands off Gigabit Ethernet on an RJ45; you take that into SFP port 25 or 49 via a 1000Base-T copper module, or directly into a copper port. Keep the PPPoE termination on a router upstream of the switch. The switch sits at L2; do not run PPPoE on the access layer.

What about MeitY DPDP compliance for subscriber data?

The switch itself does not store personal data in normal operation. MAC tables and ARP caches are transient. Backup configurations may contain SSH key fingerprints and admin usernames; encrypt the backup tarballs at rest using GPG AES256, and audit-log access to the backup Git repo. Retention default for ISP session logs under the DoT licence is 180 days minimum; the switch logs feed into your central syslog server, which is the legally responsible system.

How long is the standard Ubiquiti warranty in India?

One year on most USW switches as sold through authorised channel partners. The carton must have a BIS CRS sticker and the serial must match the UI portal. Grey-market units from Dubai or Singapore are NOT covered by India RMA, even if the warranty period is still valid globally.

What is the RMA turnaround for a USW switch in India?

Typical end-to-end is 18 to 28 calendar days through an authorised reseller. Direct UI RMA can be faster if you are a registered Ubiquiti partner. I keep a cold spare to avoid being stuck.