90-Second Rapid Diagnostics Hub
Follow our progressive "Common Denominator" steps below to resolve physical power, cabling, DECT vs. Wi-Fi cordless, and audio issues in under 90 seconds—without waiting on hold or scheduling a site visit.
Before Troubleshooting Any Specific Symptom, Check These 4 Common Denominators:
Desk Phone Screen Is Completely Blank
Common Check: Confirm whether adjacent desks have power. Check that the Ethernet cable is seated in the phone's LAN port and that the wall jack patches into an active PoE switch port (or that the 48V power brick hasn't come loose from the power strip).
Screen Shows "Network Link Down"
Common Check: The phone has power, but no data link. Reseat both ends of the Ethernet patch cord (behind the phone and at the wall jack). If a computer is daisy-chained through the phone, test plugging the phone directly into a known-good wall jack.
Screen Shows "No Service" or "Unregistered"
Common Check: The phone is connected to your local network but cannot reach the cloud core. Verify your office internet is working on a computer, then power-cycle the phone for 15 seconds. If your IT vendor recently updated firewall rules, notify us.
DECT Cordless Won't Ring (Poly® Rove, etc.)
Inbound Check: DECT handsets pair to a local DECT base station. If the handset has signal bars and can dial out—but does not ring on incoming calls—verify Do Not Disturb (DND) is turned off, turn up the handset ringer volume, and ensure the extension is logged into its ring group.
DECT Cordless Can't Make Calls / "Out of Range"
Outbound Check: Walk closer to the DECT base station (Poly® Rove, etc.). Check that the base station's power and Ethernet lights are solid green. Unplug the base station for 15 seconds to re-establish handset sync.
Wi-Fi Phone Won't Connect or Drops Calls
Wi-Fi Check: Unlike DECT phones, Wi-Fi phones connect directly to your office wireless access points (APs). Open the phone's Wi-Fi menu to verify it is connected to the proper voice SSID, confirm the Wi-Fi password hasn't changed, and check Wi-Fi signal strength in that area.
Crackling or Static on the Handset
Isolation Check: Press the Speakerphone button during a call. If the audio is crystal-clear on speakerphone but crackles on the handset, the coiled handset cord or handset receiver is worn—swap the curly cord with a neighboring phone to confirm.
Choppy Audio, Delay, or One-Way Audio
Network Check: Choppy or one-way audio typically indicates local ISP bandwidth saturation or a firewall NAT session hiccup. Pause large file uploads/backups, verify your ISP connection speed, and reboot your ISP modem/router if authorized by your IT team.
Calls Go Straight to Voicemail
Status Check: Look at your phone screen or NEXUS UC™ app for the DND (Do Not Disturb) icon or active Call Forwarding rules. Press the DND softkey to clear it, and verify your office holiday/after-hours override isn't toggled on.
Mobile or Desktop App Isn't Ringing
App Check: On smartphones, toggle Wi-Fi off to test over 5G/LTE cellular data (isolating local Wi-Fi firewall blocks). Confirm "Notifications" and "Microphone" permissions are enabled for the app in your phone/PC settings and that Focus/DND mode is off.
Physical Fax Machine or MFP Won't Send/Receive
ATA Check: Verify the phone cord from the fax machine is plugged into the LINE port on the fax machine and the active FXS/Phone port on the analog adapter (ATA). Power-cycle the ATA for 15 seconds and ensure the fax machine's baud rate is set to Basic/9600 (ECM Off).
Analog Guest / Resident Room Phone Has No Dial Tone
Room Check: Test plugging a known-working analog phone into that room's wall jack to rule out a broken handset cord or damaged phone. If multiple rooms on the same wing lack dial tone, check power and link lights on the Grandstream® FXS gateway in the telecom closet.
If Your Issue Persists, Our Engineering Team Is Ready to Step In
Submit a categorized support ticket and let us know which of the 90-second checks you already ran so we can skip the basics and go straight to root-cause diagnostics.