About a 1.5 years ago the Wifi on my iPhone 3G 8GB died. The toggle on Settings allows me to switch Wifi on but it searches and finds nothing, not even if I put the phone right next to the access point. Sometimes, but very very very VERY rarely it will find Wireless connections, even ones that are far away but it will disconnect after a few (maybe 30?) seconds. But this is very rare.

I had tried the following to fix:

Restart Phone
Reset Network
Reset Everything
Restore
Upgrade & Downgrade
Push Fix (From Cydia)

Bluetooth, GPS, 3G and everything else, even Youtube all work fine. On a side note, when the phone is put against the face the screen does not turn off as its supposed to do.

In Settings, General, About the Wifi Mac address and everything else shows up as fine.

I tried using iRecovery -S while phone is in Recovery Mode and the typed "radio readnvram" but that gave no output. But having said that i tried the same test with my iPhone 4 and even THAT gave no output when i know the Wifi works fine on it.

Is it possible the Bootloader or something is screwed up? Anything I can try Via software that i have not tried yet ?

The phone currently has 3.1.3 Jailbroken firmware.