on 14-01-2021 17:01
My partner recently gifted me her old Samsung Galaxy J3 (2016), which she used under O2 contract for several years. She is no longer with O2 but we retain details of the legacy account, and obviously can access device data on the J3.
I obtained an EE SIM to put in the J3. First off, I made the mistake of not first activating the EE SIM online, so that when I input the 4-digit SIM unlock code it had no effect. Thus the phone prompted for a “SIM network PUK”.
I assumed that the ‘network’ apparently ‘locking’ the card was the one providing the card (EE), so I entered the PUK provided by EE, multiple times (definitely more than three). All attempts showed ‘unsuccessful’.
I activated the EE SIM card online, checking that it worked in another, older Samsung phone (it did, and still does).
Back to the Galaxy J3: I re-inserted the EE SIM and tried again, multiple times (more than ten) with the PUK provided by EE with the new card.
After numerous ineffective PUK entries, I contacted O2. They provided me with what their automated email calls an “unlatch code”. This response suggested that the J3 might in fact have been network-locked to O2 all along, although the device gives no explicit sign of this.
When prompted again for “SIM network PUK”, I tried the O2-provided unlatch code instead, but to no avail.
I have now tried two different codes multiple times. Any such action prompts the same ‘unsuccessful attempt’ message, and a notification on the phone stating: ”Invalid SIM card. Network locked SIM card inserted”.
Again, this message does not specify which of the two possible ’networks’ is ‘locking’ the card (EE or O2).
I have guessed (but am not sure) that either my multiple inputs of two different PUK codes has resulted in my J3 becoming ‘frozen’, or that the phone was always locked to O2; either way, that the phone requires unlocking at the level of MCK code, or deeper.
I understand that an MCK or “unfreeze” code needs to be obtained by the original (now legacy) provider in liaison with the device manufacturer. @LukasB on this forum has requested an MCK for my phone, after I passed on details of the original O2 account associated with the phone.
- Have I done all that I can do?
- Does it seem likely that an MCK is what I need? Should I just wait for it?
- Is there a way to find out precisely what level of lock (if any) is in place on a Galaxy J3 (2016) running Android 5.1.1?
I’ve tried some admin/service codes that can be input via the phone keypad. Some work, but those that have to do with levels of lockout or freeze don't prompt a response of any kind from my phone.
Thank you, in anticipation, if you have anything to add.
Solved! Go to Solution.
on 14-01-2021 18:22
Looking at your post looks like the device was taken out in someone else’s name, so I wouldn’t be able to pass security through O2 Community to look into the account.
However, looking at your post looks like you have taken to right steps to obtain a MCK code, It would be best to wait for a response from Lukasb with the code.
It can take up to 7 days for the code to be retrieved as we have to request it from the manufacturer.
on 14-01-2021 18:39
Thanks for your quick response @O2Waqas ,
Yes, the device was associated with my partner's old O2 account. The relevant details have been passed to LukasB to enable him to request the MCK code, but I wouldn't put them in a public post.
I will heed your advice to wait a bit and try the officially-provided MCK code before doing anything else - even though the phone itself gives no sign of needing anything other than a 'network PUK'...
on 14-01-2021 18:54
@Mr_A_Stones Because the network unlock code has been entered incorrectly too many times, the phone requires a MCK code, but requests it as a sim network PUK. Once the MCK code is entered it will then ask for the networks unlock code. Once you receive the MCK code this will include all the instructions and the correct network unlock code.