Trouble connecting to DiGi Malaysia cellular network

[cjee]

I have problem connecting Xperia XZ to DiGi Malaysia mobile network. The phone keeps connecting to 2G/EDGE and does not automatically connect to LTE. Furthermore, the 3G network is not detected at all. I have already reset the phone, done a software repair with Xperia Companion, tried safe mode and swapped SIM cards. Nothing works.

Below are pictures that show Xperia XZ (right) compared to Xperia Z3 (left). As can be seen, both phones are set to LTE(preferred)/WCDMA/GSM and Automatic search mode. Both phones are using the same mobile plan. The Xperia Z3 works as it should but the Xperia XZ does not. I have already tried swapping the two SIM cards and the XZ still has the same issue.

The Xperia XZ model number is F8332 and build number is 39.0.A.1.250. SIM is inserted in slot 1.

[Uliwooly]

Is your new device compatible with your carrier's 3G and LTE bands? 

Some carrier networks require to enter the IMEI number on their database so they can enable LTE.

[cjee]

The Xperia XZ can connect to LTE if forced to but it has the tendency to stay on 2G/EDGE. It sometimes fails to connect to LTE at all though. In addition, when connected to LTE, phone calls do not come through as it does not reliably switch to 2G/3G upon the call as well. The Xperia Z3 does not exhibit this behaviour. The Z3 switches to 3G immediately during a call and immediately switches back to LTE when the call ends. It virtually never connects to 2G/EDGE as the 3G and LTE signal here is not bad.

I checked gsmarena and found that the Xperia XZ supports all the bands that the Xperia Z3 I have (D6653) supports. Since the Xperia Z3 can connect fine, I do not think it is an issue with the Xperia XZ's bands. Moreover, the Xperia Z3 can connect to all 3 types of network fine without submitting any info to the carrier. I do not understand why the XZ is unable to see the 3G network at all when the Z3 can and both have the same band support.

I have already asked DiGi before posting here and was told to look for the phone manufacturer.

[Uliwooly]

You can contact Sony directly to get the device inspected >>> Local support

[cjee · Accepted solution]

It was a faulty mainboard. Hope that in the future Sony will catch these kind of issues before the phone leaves the factory.