My phone show wifi signal but wifi is not work in my moblie

Go to Settings, click on WIFi, click on the three dots on to top right of the screen, select Advanced Wi-Fi, then turn on Auto Connect to WiFi and Wi-Fi Notification

Make sure the wifi connection setup in your ZTE is still working, and you are close enough to the WiFi router to receive the signal. I assume the connection worked before.
Be aware WiFi can become bad when the router is not in the same room. Concrete walls are killers for WiFi signals.

I suppose that what you mean is that you can access your wifi networks but not your service provider's network.

If that's what you mean, check the user's manual CLICK HERE page 122.

Do you see a G/2g/4g by the signal bar on your phone? Can you make an outbound call/Receive a call?
If you don't see the G, that means the phone is not connecting to the network. If you can make a call, that means it's connected to the tower. Try shutting the phone down, then restarting. If you can't make a call, for some reason, it would seem like your phone is not detecting your SIM. Shut the phone down, remove the battery, and reinsert the SIM. Let the phone sit for about 2 minutes, reinsert the battery, then power up. That should allow you to get back online. Worst case scenario, contact Tmo tech support or go to the local store for assistance

I’m happy to help further over the phone at https://www.6ya.com/expert/susan_42b401e0b1603d8a

Check weather any other device can detect wifi signal of your modem router. If it cannot detect the signal then it may be the complaint of your modem roter wifi.
If the other device can detect wifi of your modem router then back up the data of your phone and reset it. It will work fine.
Thank you

Your Nokia phone will see 802.11 b/g signals. Is your home access point broadcasting one of these?

Fast answer is take the battery out of the phone. Let your phone refresh and then you should be able to send your mms out. Make sure that your wifi and moblie network aren't on at the same time. Your moblie network actually is how your phone is sending out data.

I’m happy to help further over the phone at https://www.6ya.com/expert/ronald_e152e07e272e4f27

THe sim has nothign to do with signal (as long as the SIM is valid). Change carriers or switch phones. I live in a spot where my wife's iphone works with one bar but my Ipaq gets no signal (both AT&T). So phones can differ in signal performance - try your sim in a different phone or switch carriers.

u want to change or repair the antena switch

I have bought a new 6300 phone housing on eBay. changed housing front and back,new buttons. changed motherboard,replaced everything carefully and correctly. the mobile turns on and shows everything as normal,,,, but shows Sim card not registered , wont charge, it plugs in and show data protection or something????? and shows no signal. I have worked at plenty of mobile phones replacing parts , this is over my head please help thank you.