When a SIM isn't behaving the way you expect (won't attach, attached but no data, attaches intermittently), the Diagnostics tool is the first thing to run. It's one click in the dashboard, completes in seconds, and surfaces the obvious causes before you spend time digging.
This article explains what Diagnostics checks, how to run it, and how to interpret the result.
What Diagnostics checks
The check runs across three layers:
1. Provisioning (SIM-side)
Is the SIM Enabled?
Is it on a plan that covers the country the device is in?
Is throttling active (rare; usually set per plan)?
Is Theft Protection locking the SIM to a specific IMEI that doesn't match the current device?
Is there an enforced data cap (Usage Limits) that's been reached?
2. Network
Is there a known incident affecting the area the SIM was last seen in (or is in now)?
Are there issues with the SIM profile (for example, a carrier outage on one of the operators the SIM profile uses)?
Has the device recently opened a data session (proves the radio is working)?
Has the device attempted registration recently (proves it's at least trying)?
3. Hardware
Do the bands and frequencies of the device hardware match what the local carriers use?
Common cause of attach failures: a device built for one region (say, North America) deployed in another (say, Europe) where the bands don't overlap.
Run Diagnostics
Sign in to dashboard.simbase.com.
Open the SIM you want to check.
Click Diagnostics (usually top-right of the SIM detail page).
Wait a few seconds for the check to complete.
The result lists each check with a status:
Pass: no issue found at that layer.
Warning: possible issue worth investigating but not necessarily blocking.
Fail: likely root cause; fix this first.
Interpreting the result
Most connectivity issues fall into one of a few patterns:
| Diagnostics result | Likely cause | Next step |
|---|---|---|
Provisioning Fail: SIM Disabled | The SIM was disabled manually, or automatically by Usage Limits, Theft Protection, or a zero account balance | Re-enable the SIM. If the balance reached zero, top up first. See SIM state and Account balance. |
Provisioning Fail: Wrong plan for country | SIM is in a country the current plan doesn't cover | Switch plan. See Coverage. |
Network Fail: No recent registration | Device isn't attempting to register on the network | Check power, antenna, SIM tray, signal strength at the location, and device configuration. |
Network Warning: Carrier incident in area | Known operator outage. Your SIMs may be impacted. | Wait for the incident to clear, or contact support for detail. |
Hardware Fail: Band mismatch | Device might not support the bands used by local carriers | Confirm the device supports the local bands. May need different hardware. |
All Pass but SIM still not working | Likely an APN or device-side configuration issue | Check the APN (Set up the Simbase APN). |
Provisioning Fail: SIM Disabled
Provisioning Fail: Wrong plan for country
Network Fail: No recent registration
Network Warning: Carrier incident in area
Hardware Fail: Band mismatch
All Pass but SIM still not working
When to escalate to support
Run Diagnostics first. If the result is unambiguous (for example, wrong plan, disabled SIM), fix it and re-test. If the result is ambiguous, or if everything passes but the SIM still doesn't work, contact support and include the Diagnostics result in your message, so the support engineer doesn't have to re-run it.
Run Diagnostics via API
For programmatic checks (fleet-wide health monitoring, automated alerts), Diagnostics is also exposed through the Simbase API. Useful when you want to:
Run Diagnostics on every SIM after a network incident
Build a dashboard view of provisioning health across the fleet
Trigger a Diagnostics check as part of an incident-response runbook
See the API documentation for the endpoint and response format.
Common questions
Real-time for provisioning checks (it queries the current SIM state directly); near real-time for network checks (uses the most recent attach data, usually seconds to minutes old).
Check the device's APN configuration, see Set up the Simbase APN, and confirm data roaming is enabled on the device. If neither is the issue, contact support with the Diagnostics output.
Not from the dashboard UI today. It's per-SIM. For fleet-wide checks, use the API.
Yes. At zero balance Simbase disables every SIM on the account, which Diagnostics reports as Provisioning Fail: SIM Disabled. Adding funds restores them within minutes, with no manual re-enable needed. Auto-recharge prevents it happening at all.
Related
SIM state, fix Enable/Disable issues
Coverage, fix wrong-plan issues
Theft Protection, fix IMEI lock issues
Set up the Simbase APN, the next thing to check when Diagnostics passes
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