Original XT-DUAL: SAT/GSM mode, registration and data

Work through these checks

1. 01

   Read the existing network preference

   View Menu → Network → System preference without selecting another value. Record SAT only, SAT preferred, GSM only or GSM preferred alongside the current SAT/GSM indicator. Preferred modes try their preferred network first and can use the other if it is unavailable. Their existing rescan interval can be 15, 30 or 60 minutes; do not change it or force a search for this check.

   What the result means: A preference is not proof of the currently used network. A handset waiting on the fallback network between configured searches is different from a unit configured never to use that network. Preserve that distinction for support rather than treating every mode difference as hardware failure.

2. 02

   Separate the SAT registration warning from HPA

   Record whether SAT is blinking and whether the displayed service area is correct. The original warns that either problem can prevent SAT calls and states that SAT registration works only in satellite mode. HPA is a weak-signal incoming-call notification, separate from the Active call symbol. Preserve the exact existing warning; do not initiate registration or another call merely to diagnose the earlier failure.

   What the result means: A registration or service-area warning is different from an incoming alert that has not become a call. Give the provider the mode and exact warning together; HPA alone does not establish adequate voice reception or current account permission.

3. 03

   Read existing data and call-priority evidence

   For the original failed data activity, inspect the existing GmPRS/GPRS access-point record and bearer without editing fields. The manual distinguishes GmPRS/GPRS from CSD and says the provider must support and, where necessary, activate the feature for the SIM. Record the APN supplied for that service privately; do not replace it with an old example. For an incoming-call failure while GmPRS was active, also read the existing Auto reject setting.

   What the result means: The provider can separate network permission, the installed data profile and deliberate incoming-call rejection during GmPRS. None of these is established by signal bars alone, and a historical USB driver or APN example is not proof of present compatibility.