I just upgraded to OS 4.2 and my wifi/3g Ipad wouldn't recognize the 3G network. After several hours I discovered the following post over on the Apple Support Forum- worked like a charm (from Dr. Technical
I had 3G problems after upgrading to 4.2.1, with the following symptoms:

• Network status indicator (upper left corner) showed "No Service" instead of "AT&T 3G" (and, of course, no cellular connectivity). Wi-Fi worked normally.
• No "View Account" button on Cellular Data screen in Settings
• Under "About", Carrier and Cellular Data Number showed as "Unknown" or "Unavailable"

I called Apple tech support and went through some troubleshooting procedures. Here's what finally worked for me:

• Bring up the Settings app
• Set "Airplane Mode" on for a short period, then turn it back off.
• Under "General", choose "Reset" then select "Reset Network"
• Confirm that you want to reset all network settings
• Power the iPad completely off then turn it back on

Wow. Thanks for the info.

Thanks for the info. DrJ.

Hello

I tried that with no luck. I am still in GPRS/Edge here in Belgium.
I swapped my card with the one of my iphone 4 and no luck, both sims are however working fine on my iphone and 3G is showed.
On my ipad no 3G juste the little circle for GPRS.
so tried reset network, tried to reboot and airplane mode, no luck.
Was in 3.2.2. and went for 4.2.1 -> no more luck.

Anyone another idea ?

Chris

Nice tips, thanks a lot!!
Well, guys must also be interested in reading this tips "Tips to Turn iPad Wifi Into 3G"- learn how to get your iPad WiFi connected to 3G network. especially for those wifi users

You provided good information to get 3G back on iPad. Thanks for such useful information. I will use it in future when I will come across a problem like you. I save this information for the future reference.

Originally Posted by chrisjones

Hello

I tried that with no luck. I am still in GPRS/Edge here in Belgium.
I swapped my card with the one of my iphone 4 and no luck, both sims are however working fine on my iphone and 3G is showed.
On my ipad no 3G juste the little circle for GPRS.
so tried reset network, tried to reboot and airplane mode, no luck.
Was in 3.2.2. and went for 4.2.1 -> no more luck.

Anyone another idea ?

Chris

Try inputing the APN information under the Cellular Data settings.

I have a similar problem but the symptom is different.

I leave the GSM network coverage until the signal is totally lost. I am able to use wi-fi. GSM is totally out (obviously). Then i return back to the GSM coverage, on the status bar, NORMALLY it should show <Provider Name> then "3G". But for me, it will only show the provider name and when i open Safari, it says there is no network coverage, same for all Apps. When i turn off the "Cellular Data" manually, it will go to "Ipad" then turning "Cellular Data" back on will bring me back to the Provide name without "3G".
I had to reboot the ipad to get the service back.

This has happened 3 times already after I upgraded to 4.2.1