I am using android based Samsung’s Galaxy Pop CDMA (SCH-I559) cell phone. I was eager to connect to internet to access the Web on my cell phone. But, whenever I was accessing the web based apps (Play store, gmail, etc) on my cell phone, it asked for a Gmail credentials. I gave my Gmail credentials but it gave the error message “Can’t establish a reliable data connection to the server”
On Web, I searched about this problem. Results show the only solution is that “you need to reset the phone”. The problem with resetting the phone is that, you lose all the data. I found the solution in that you will not lose the data.
Firstly, I want to tell you, why phone displays such error when you tried to use apps. When you start your android phone first time then you need to configure the account with Gmail address. If you ignore that configuration then you will get the above message when you access the apps.
Note: I think, this trick may work on all android phone
To rectify the problem, you just access Youtube app from your android phone (But you need your Google credential attached to Youtube.com account. For that, on computer you login on Gmail and then on another tab open Youtube.com. You need to signin with Google credentials). Now go to Youtube App and login with Google credentials.
After you have signed in via the Youtube app, exit the Youtube app (without closing the app; by pressing the Home button) and go to the main Android Settings menu. Then go to Accounts and sync. In Accounts and sync, you will see email id that you used to login in Youtube app; tap on that account. After the account has been brought up, check the checkbox for Sync Contacts or Sync Gmail, this will synchronies Google account.
Now, you can tap on Gmail or Play store app, it will automatically login in that app with Your Google account details.
It is very important to configure Google account, as per my experience. I have applied visible pattern to my cell phone. My little cousin drawn tried a lot wrong pattern and the visible pattern was trapped. I thought, I should have to update the phone’s firmware and I will lose my all data. There is one option, “Forgot pattern?”, but it ask Google credential but I thought it will not work because there is no data plan was activated on phone. But I entered the Google credentials and that was accepted and I got my phone’s desktop.
(Images are copied from Web just for explanation)