FAQ
TL;DR: 0 calls or texts work on an IMEI‑blocked phone; "Overall, the entire network is down." This FAQ explains checks, Samsung Knox behavior, and realistic next steps. [Elektroda, br501, post #19501192]
Why it matters: It helps buyers and fixers avoid dead‑end purchases and wasted repairs when asking how to unlock a network‑locked phone.
Quick Facts
- IMEI‑blacklisted devices have no voice, SMS, or data service across networks. [Elektroda, br501, post #19501192]
- On Samsung, a network/Knox lock can re‑lock after going online, even with a code. [Elektroda, blahfff, post #19499431]
- Unlocking the bootloader can trip Knox and break banking app compatibility. [Elektroda, blahfff, post #19500025]
- Buying unpaid‑contract phones risks police involvement; Samsung can block via IMEI or Knox. [Elektroda, rafal3108, post #19502895]
- Water‑damage salvage report: after an ultrasonic clean plus ~10‑minute isopropanol bath, one device revived. [Elektroda, DJF1, post #19752488]
How do I check if a phone is IMEI‑blocked or just SIM‑locked?
Insert a known‑good SIM and try calling and texting. If you cannot place calls or send SMS anywhere, the IMEI is likely blacklisted. You may also see no network despite good signal. SIM‑locked phones usually work with the original carrier’s SIM. IMEI‑blocked units have zero network services. [Elektroda, br501, post #19501192]
Can I remove a Samsung network/Knox lock?
"It is not possible to remove this lock, at least if it is already activated." Even with a correct unlock code, it re‑locks after the phone goes online. Treat such phones as parts donors, not daily drivers. Bypass attempts tend to fail once the device contacts servers again. [Elektroda, blahfff, post #19499431]
Is flashing or bootloader unlocking a reliable workaround?
Not reliably. You can unlock the bootloader and flash software without Knox, but you lose functionality. Banking and other apps detect an unlocked bootloader. Many will refuse to run. "Either upload another soft ... or keep the bootloader unlocked," but both have trade‑offs. Consider the usability hit before trying. [Elektroda, blahfff, post #19500025]
Will an IMEI‑blocked phone work on any carrier?
No. IMEI‑blocked devices fail at the transmitter level. Calls and texts do not go through on any network. "Overall, the entire network is down." Data service is also unavailable. Swapping SIM cards will not help. The block follows the device identity, not the SIM. [Elektroda, br501, post #19501192]
Do operators ever IMEI‑block Samsung phones?
Yes. Despite claims that Samsung avoids blacklisting, technicians report IMEI‑blocked Samsungs. This means you cannot assume a Samsung is safe from blacklist enforcement. Always verify status before purchase. A blacklisted Samsung will behave like any other blacklisted phone on network services. [Elektroda, br501, post #19502772]
If a startup warning says it might be blocked, is it safe to buy?
No. Such devices can lock or re‑lock after they connect to the internet. Remote actions can change the lock state once the phone has Wi‑Fi or cellular data. If the IMEI becomes blacklisted, network unlock paths also close. Buying remains risky and unstable. [Elektroda, blahfff, post #19501767]
What happens when a locked Samsung goes online?
After connecting to the internet, Samsung’s lock can re‑assert. Even with the correct unlock code, the device can lock again. This behavior defeats many one‑time unlock attempts. Expect the lock to persist once servers are contacted. [Elektroda, blahfff, post #19499431]
Can remote unlock work without Wi‑Fi?
Yes, but only if the phone has a SIM with a data connection. If no saved Wi‑Fi exists, a data‑enabled SIM is required. Edge case: when the IMEI is blacklisted, that cellular data path is blocked. Remote unlock then fails. [Elektroda, blahfff, post #19501767]
Is it legal or safe to buy unpaid‑contract phones?
It is unsafe. A reported buyer received a police visit over an unpaid operator device. Samsung can block it by IMEI or via Knox. The practical advice was clear: buy a new phone and do not try to outmaneuver the lock. [Elektroda, rafal3108, post #19502895]
How much does professional unlocking cost in this scenario?
There is no dependable service for these locks. A contributor noted no guarantee and frequent changes by operators and Samsung. That means paying for attempts is risky. Costs can be wasted with no lasting result. "There is no guarantee for it." [Elektroda, blahfff, post #19501767]
How can I try reviving a water‑damaged board?
One success report used this sequence:
- Ultrasonic‑clean the board in appropriate bath liquid.
- Rinse with isopropanol for about 10 minutes.
- Dry thoroughly, then test.
The device "came to life and works to this day" after this process. This is not guaranteed, but it can help. [Elektroda, DJF1, post #19752488]
Is replacing the motherboard worth it on a newer phone?
Often no. The original poster noted the board was costly or unavailable, making replacement uneconomical. In such cases, part out the device or repair only feasible modules. Consider total cost versus buying a working replacement. [Elektroda, DJF1, post #19499384]
If I enter a correct unlock code, will it stay unlocked?
Not on a Samsung with an active lock. Once it connects to the internet, it can lock again. This re‑lock behavior makes code‑based unlocks unreliable for long‑term use. Expect the device to revert. [Elektroda, blahfff, post #19499431]
What’s the best use for a permanently locked phone?
Use it for parts. An experienced poster advised these phones are only suitable for parts other than the whole motherboard. Do not plan on carrier service or daily use. Salvage screens, cameras, or housings if viable. [Elektroda, blahfff, post #19499431]
