Diagnostic Checklist & Reference Navigation
Find the carrier, seller or manufacturer responsible for a device issue and gather the model, error and order details they need.
For an account, activation or return issue, contact the provider responsible for the transaction. The checks below help you give them useful information.
Who handles the issue?
| Issue | Contact | Prepare |
|---|---|---|
| SIM lock, billing or failed activation | Original or intended carrier, as appropriate | Model, order/account details and exact error |
| Refurbished condition or missing accessories | Seller shown on the order | Listing, delivery photos and return deadline |
| Battery or hardware fault | Manufacturer or authorized service provider | Model, software version, symptoms and service messages |
| One app drains battery or misses alerts | App developer through its official support | App version, battery settings and reproduction steps |
Use the official provider website or your account’s support channel. Share IMEI and account information only through their private support process, not a public comment or forum.
Checks to collect first
Record the full model number in Settings → About, the operating-system version and when the issue started. On iPhone, inspect Carrier Lock under Settings → General → About. On Android, use the carrier’s instructions for the specific model; menus vary.
For a delivery issue, compare against the written grade and battery promise. For a connection issue, note whether calls, texts, Wi-Fi and mobile data fail separately. For drain, save a Battery usage screenshot for the affected period.
Continue with refurbished checks, carrier unlocking or mobile troubleshooting.