S4 doesn't detect any WiFi I helped my fried to convert from Iphone to S4. I helped him with initial setup and gave some quick crash course. I visited him after a week and answered a few of his questions. I again visited him today after a week. But his Galaxy S4 GT-I9500 has developed a problem.


The WiFi would stuck on "Turning on" if Bluetooth is switched off.
The phone won't detect any WiFi. I tried with multiple AP with different settings and even without security.
It detected the APs for few seconds once during this troubleshooting time of three to four hours.
Resetting didn't help.


The phone is currently running Android 4.2.2. Any idea on how to make it detect the AP? I'll be trying to flash Android 4.3 via Odin tomorrow. I couldn't do it via Kies as it would say an unknown error occurred.

UPDATE: So I've pushed WiFi Analyzer and playing randomly with WiFi Settings and WiFi analyzer brings WiFi back for good. But same problem after factory reset. And again repeating above actions fixes it.
Is it using a custom ROM or a modified stock ROM?

Flashing DjeMBeY's pre-rooted S4 ROMs has issues with Wi-Fi, esp. for those higher than MGA. They have a Wi-Fi fix, but I still encountered issues (e.g. intermittent mobile data, loss of audio / sound). So, I downgraded back to MGA.

Hopefully reading the thread in XDA might give you some ideas. Do share your answer if you find something useful, or a solution.