For those who know, my Samsung Galaxy A73 5G is having problems with the network. I bought this phone in South Africa and then went to use it in Tanzania for two years and I never had any challenges with the network. But the problem started when I returned to South Africa. With this phone, some sim cards do not work. There is only one network, Cell C, that I can use.
Hi That’s actually a fairly common issue when a phone has been used across regions — especially between countries like South Africa and Tanzania. Let’s break down what might be happening with your Galaxy A73 5G and why only Cell C seems to work now:
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🔍 Possible Causes & Fixes
1. Network Lock / Region Lock
Samsung devices bought in one region (like Tanzania) may have a regional lock that only fully activates after a certain number of local calls are made in the region of purchase.
However, since you did use it abroad already, the region lock should have been lifted.
But sometimes, re-entering the original region (South Africa) can confuse the network settings or modem firmware.
✅ Fix:
Go to Settings → Connections → Mobile networks → Network operators → Turn off “Select automatically,” and try manually selecting MTN, Vodacom, or Telkom.
If the SIMs fail to register, note the error message (e.g., “Not registered on network” or “Emergency calls only”).
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2. Network Band Compatibility
Tanzanian carriers and South African carriers may use different frequency bands for LTE/5G.
If your A73 variant doesn’t support some South African LTE bands, it will struggle with certain networks.
✅ Fix:
Dial *#0011# → check the band number your phone connects to on Cell C.
Compare with MTN or Vodacom’s supported LTE bands (they use mainly B3, B7, B20, and B28 in SA).
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3. SIM Slot or Firmware Problem
Sometimes one SIM slot or the modem software gets corrupted after region changes or updates.
✅ Fix:
1. Test each SIM slot separately.
2. Try flashing the latest official South African firmware (XFA CSC) using Smart Switch or Odin — this reconfigures the network settings for local carriers.
3. Before doing that, back up your data.
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4. Carrier Restrictions
In rare cases, the IMEI could be blocked or partially restricted by some South African networks (e.g., if the device was reported, even mistakenly).
✅ Fix:
Dial *#06# to get your IMEI.
Visit the ICASA or SAPS CEIR (IMEI check) site, or call your carrier’s customer service to verify the IMEI status.
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5. APN / Network Settings Reset
Sometimes, old Tanzanian carrier settings cause conflicts.
✅ Fix:
Go to Settings → General management → Reset → Reset network settings.
Restart the device, insert the non-working SIM, and check if the carrier settings update automatically.
