[Xperia Z3 Compact General] mikuru396:
Part 3: Unlock LTE band(s)

29. Make sure you have unlocked "[60] Reserved for BC10-1700" in previous part.

30. Go to Start -> All Programs -> QXDM Professional, open "QXDM Professional". In the top menu select "Option" -> "Communication".

31. Under "All Ports in System:" select your port (should me same port as you use in QPST) and press "OK. QXDM should load all data automatically once you press ok.

32. In top menu, select "View" -> "New" -> "Common" -> "NV Browser". In the newly opened window, select "LTE" next to the "Category Filter".

33. Select the item with ID 06828 (Description = LTE BC Config, Full Path Name = LTE_BC_CONFIG). It should display "input" and "Value" of 0 under "Fields".

34. Press the "Read" button in the lower right corner, it should show a non-zero number under "Value". Please also write it down for recovery.

35. Convert the number, noted at step 34, to binary form. It will show which LTE bands your phone currently supported ...

35a. Start reading from right to left, the 1st digit from the right (right-most) will be corresponding to LTE Band 1, the 2nd digit will be for LTE Band 2, the 3rd digit will be for LTE Band 3. So the rule will be [ N-th digit will be for LTE Band N ].

35b. For each digit, 1 means the phone support that particular band while 0 means no support. For example in D5833, it should be 549890031829 = "1000000000001000000000000000000011010101" (LTE Band 1,3,5,7,8,28,40).

35c. So if you want to unlock some LTE band(s), filp such bit to 1. In case you have a gap like band 28-40, make sure you fill it with 0, or you will fail to unlock such channel.

36. Please work out our own value that suit your need. In my case I need LTE Band 1,3,5,7,8,9,19,21,28,38,39,40,41 so my value will be "11110000000001000000101000000000111010101" = 2061719830997

37. Go back to QXDM, double-click the 0 under "Input", replace it with the number you calculated at step 36 in decimal form.

38. Write the value to your phone by pressing the "Write" button next to "Read" button.

39. Close and reopen QXDM. Repeat step 31-35 and double check the number under "Value".

40. Close QXDM, unplug your phone and reboot it. If you got reception after reboot, then you are good. Please give thanks to [MENTION=5733862]BlackSoulxxx[/MENTION]

40a. Open dialer, type *#*#7378423#*#* (*#*#SERVICE#*#*), goto "Service info" -> "Configuration", you should see your unlocked band. If not, that means your phone reset it while reboot. You can do nothing unless you know how to disable the reset.

40b. If your phone cannot get signal after the mod, flash your phone with the stock FTF, do NOT select anyone under "Wipe:", select all under "Exclude:" but keep "BASEBAND" selected. This should flash the originial baseband firmware, hence remove this mod.

40c. If you still cannot get any reception, flash the whole stock FTF. This will wipe all your data, but reset it to factory installed status.

41. If you still cannot connect via LTE, open dialer and type *#*#4636#*#* (*#*#INFO#*#*), find "preferred network" and select "LTE".

41a. If it fail to connect, either is hardware restriction, or more software setting has to be done (some carrier has different APN for 3G/LTE)

42. You are done for this section, please continue for quitting diagnositc mode.