Bd26100. How can I get to turn on?

Check the settings for the vibrate mode.
Have you put the phone on 'Silent'?
Go into Settings,
Go to Sounds and Vibrations.
Turn 'Sound mode' to Sound.
Turn 'Vibrate while ringing' to on. (Move the dot right).
Turn 'Vibration intensity' to a higher setting, (Move the dot right).
Scroll down to 'Do not disturb'. Turn off. (Slide the dot left).

What phone you have would be useful to know but for

Android : How to Turn off Sound and Vibration in Androids Keyboard

Iphone: If you set the iPhone to vibrate in silent mode, it still makes an audible buzzing sound that may bother or disrupt others. If you need your iPhone to stay completely quiet, temporarily disable vibration. You can turn off vibration when silent mode is on, off or both. Tap the button next to "Vibrate on Ring."

Blackberry:
Turning vibration on my mobile phone on or off

1. Find "Notifications" Slide your finger down the display starting from the top edge of your mobile phone. ...
2. Turn vibration on or off. Tap the indicator next to Vibrate to turn the function on or off.
3. Exit.

1. Find "Sound"
Press the menu icon.
Press Settings.
Press Sound.
2. Turn vibration on or off
Press Vibrate and ring to turn vibration on or off.
When the box next to the menu item is ticked (V), vibration is turned on.
3. Exit
Press the home icon to return to standby mode.

Rob, assuming this is a 4X4? Sounds like a bearing. They can vibrate, snap, clunk, all kinds of terrible noises or vibrations.
Axle u joints will also do this. Is it all wheel drive?

Ok, not the remotest notion about the first part. But, you're in luck. Under Wireless Controls in Settings, airplane mode should be on there, if not, contact HTC Costumer Support about that.

hi ;(,, i forget my pasword cell phon -HTC.TD7-
i don`t know how solve my problem!

The lens block is faulty

Press and hold the * key to switch to turn "Vibrating mode on." Press and hold * again to turn "Vibrating mode off."

u edit ur profile and disable vibration first it wil automatically change ....
eg: u selecting meeting profile means u can edit that profile and turn off the vibration