Lumia 640 LTE Dual SIM No Network Found

RGood day. My problem is that I have had two sim cards in my phone since November 2015 and they have worked beautifully. Sim cards are from different providers. A week ago I started having problems with sim 1. I did a sim swop to rectify the problem. Sim 1 works in my old phone and sim 2 works in the new phone. When I put sim 1 in the new phone, neither sim card works. Sim 1 says no sim and sim 2 says no network found. I don't know if this is a hardware or software problem or a combination of the two.

In November I purchased a Microsoft Lumia 640 LTE dual sim mobile phone which I am generally very pleased with. At the moment I am only using one sim in slot 1. There is an intermittent fault that I hope you may be able to assist me with. For your information I switch the phone off at night and when switched on in the morning and after entering my pin it functions correctly. After approximately 7 days or so for no apparent reason the mobile phone signal from my mobile supplier is lost indicating “no network found” in sim 1 settings. If I transfer the sim at the same location to my old phone the signal is fine & my old phone works correctly so it is not a sim card problem. I have tried soft resets, switching sim off & on, manual network selection which have not cured the problem. The only way I have found to date to rectify the problem is to switch the phone off, remove the battery, transfer the sim to my old phone so I still have an operational mobile phone. After an hour or two I replace the sim & battery in my Lumia phone switch on and it functions correctly. When the phone indicates “no network found” I have carried out a search for networks my mobile operator is shown as one of the providers so the aerial etc. is presumably working correctly but it will not connect to the network.

I hope you can advise a solution for this problem or if you require any further information please let me know

This links redirects me to the useless

https://support.microsoft.com/en-us/products/mobile-devices/

What is there? a reset?

Thank you JG2yang1. After I inserted a second sim card the fault has not happened again. Maybe something associated with the software that as it is a dual sim phone two sims need to be inserted for it to function correctly.

Hi, Trevor_852. Thank you for posting your query on the community. You may try the suggestions on this link and see if it helps: https://www.microsoft.com/en-us/mobile/support/faq/?action=singleTopic&topic=FA141384. We look forward to your reply.