I bought a t-mobile g1 off a friend

Hi i think your mobile is locked by particular provider. So only it didn't accept your t-mobile sim card. If you need unlock your mobile you can visit this site Theunlockarena.com here you can get the code and unlock your mobile easily. To get the code you have to mentioned which country is locked now,network provider and imei number. Then they send unlock code through email . After unlock your mobile you can easily use t-mobile sim card and any other sim card in your mobile.
Theunlockarena.com

you can Unlock your HTC G1 with imei unlock code. it is very simple and eaisiat way to unlock your HTC G1. get your HTC G1 Imei Unlock Code . and use any gsm sim card.
i hope this will help you .

Your cell phone may be locked to a particular cell phoneprovider and in this case it needs to be unlocked to use with a different cellphone service provider. To get the security code/restriction code to unlock thecell phone from the current cell phone provider so you can use the SIM cardwith a different phone provider, Please click on this link and follow myinstructions :- http://www.fixya.com/support/r4049238-unlock_cell_phone If your phone provider does not help you then this WEB siteit provides security codes for a small price. http://www.mobileunlockstore.com/?gclid=CKDb2_y2558CFSlJagodxBkDHw Try this WEB sites - http://www.unlock-free.com http://www.unlock-zone.com/ http://www.unlocking.com/

DEAR FRIEND, TRY AND GET AN ORIGINAL BATTERY FOR YOUR PHONE.

you just need to use a friends sim card that has the g1 data plan and set up your gmail account and then when you put your sim card in the g1 wont ask you for the gmail account again thats what i did

I guess you have factory reset the phone and it swap out everything.

The G1's much-vaunted first step during the setup is to enter your Google login username and password. Once that happens, the G1 attempts to connect to Google's servers to get your email, contacts, and calendar set up.
Here's the thing, though, if (or when) the G1 cannot connect to the servers, you're done. There is no way to exit out of the Google setup screen, no clear way to reset the phone to bypass it (even in "safe mode"), no way to turn on WiFi.

Hi, three wrong entry of PIN code will result in SIM blocking. Once SIM gets blocked, phone starts asking PUK code to enter. If you again enter wrong code for three times, SIM gets completely blocked. You have to walk into your service provider outlet to get a replacement SIM card.

PUK code is a SIM specific code assigned by your service provider. No way you can guess & enter it. So, when it asks for the PUK code, don’t do anything, get the PUK code from your service provider.

Call to customer care using any other mobile phone which uses the same service provider. They will ask some details about you to make sure you are the owner of the SIM card. Questions might include your billing address, email ID, numbers you recently called or messaged etc. They might even ask you number printed on the SIM card, so be prepared with all details before calling them. Once you get the PUK code, enter it into the phone & your phone will return to normal.

Good luck!!!

1) You'll need to borrow a SIM from a friend of yours to access the phone.

2) Open the market and install an application named "wosim".

3) Turn off your phone and then turn it on again.

my mobile requier insert sim card.

Hi, I had that problem. I first verified that my TMobile internet was activated on my account and on my SIM card by putting the card in another phone and connecting to the 'net on it. Then I found the APN setting on the G1 and I changed the APN at the heading "T-Mobile US" from the new 3G APN "epc.tmobile.com" to the older APN "internet2.voicestream.com". The APNs can be accessed on your still-locked phone by pushing the "Menu" button at the sign-in screen. Scroll down to "T-Mobile US", select it and change "epc.tmobile.com" to "internet2.voicestream.com", exit by pushing the left-arrow button a few times, then re-enter your GMail info. If the "Edge" icon has appeared in the menu bar area, then you're golden!