Connection problem or invalid MMI code

Many android users will have meet this message on your android phone one way or another. This usually happens when u press the *,# or + and the phone button to made the call.

After u press the *,# follow by some numbers, it shows USSD Code is running and later the Connection problem or invalid MMI Code will appear. You have enter a code the system does not understand. But if u have press *#06#, it will display the IMEI Code. There are many special codes that start with * or # and follow by numbers and pressing the SEND or Phone icons.

If you start up the phone and this error prompts, it means the sim card or your phone system is automatically sending a special code to the cell phone company but not recongnized by the cell phone company system.

What is a MMI Code?
An MMI Code is a sequence of digits that is entered into your phone to make it perform some special action. These codes start and end with a * or # so they don't get confused with phone numbers you might want to dial. They're usually only valid when you're not on a call, so if you key one in while connected to your cellphone company's IVR system they won't be recognized. Some MMI Codes are dealt with by your phone – for example, there's usually one you can key in to find out what software version your phone has installed. Most MMI Codes are sent to your Cellphone company as they are used to turn features on and off (Like call forwarding, call waiting, etc).

Why does my phone say "MMI Code Failed"?
This will usually happen because your Cellphone company has decided that you aren't allowed to forward your calls. It could be because you are on a "plan" that doesn't have the forwarding feature (pre-pay/flex-pay plans usually restrict this feature). Unfortunately there is nothing we can do to 'bypass' this error – if you believe your plan should allow you to use this feature you will need to call your cellphone company and ask them to (a) let you control it from your phone, or (b) set the forwarding for you.
Note: If you go for option (b) make very sure that they only turn on "Conditional" forwarding (this only forwards Busy/No-Answer/Unavailable calls). Sometimes they'll accidentally turn on "Unconditional" forwarding (this forwards ALL calls!).

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Hard Reset HTC Desire HD

DesireHD HTC Desire HD is a fully customizable phone and you can tweak it using the settings to your likes. Do not worry if you have done the wrong things, as you can return it to the default factory settings.

Pls take note that we are not responsible for any data deleted from your HTC Desire HD. This process may or may not delete data on your Micro SD Card. Pls remember to backup any important data that u may have on your phone.

Users who are using Google to sync your Gmail,Contacts,Calendar and Docs will not loose any data as they are stored in the cloud(server).

Factory Reset of HTC Desire HD

    1. From the main Home screen, tap Menu
    1. Tap Settings, then SD & phone storage
    1. Tap Factory data reset
    1. Tap Reset Phone
  1. Enter your password if required, then tap Erase everything to confirm

If this does not resolve your problem, then hard reset it,

    1. Turn the power off. If your HTC Desire HD is frozen, pull the battery out and reinsert it
    1. Hold the Volume Down button
    1. Press and hold the Power button until the device turns on
    1. You are now presented with a menu that allows for Fastbook, Recovery, Clear Storage, and Simlock
    1. Select Clear Storage by pressing the Volume Down button
    1. Press and release the Power button
  1. Now simply confirm your decision: Volume Up for YES and Volume Down for NO

All data including third party apps on your HTC Desire HD will be deleted from the HTC Desire HD.
Once the process is complete, the HTC Desire HD will be like a new one out from the factory.

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