My 8900 is on, but none of the buttons work. And when I hit the back button to the right of the trackball, sometimes it inputs the letter "b". Other buttons sometimes work, and sometimes do what other buttons do like the back button being a "b'

Should be a button on your remote labeled input or source. If it does not it could have buttons with icons/lettering on them with a tv or spelled out tv, HDMI, input 1...2...etc. If none of these apply it can be done by hitting the Menu button, going to the video section and select input you would like. This can also be done with the menu button on your tv.

Find the button that relates to the input you want to view. IE "video" "composite" "s-video"
Or simply try any of the input buttons until the picture returns. 
Also try simply hitting the VGA button again.
If none of that works, please let me know the model number of the tv and the input sources you are trying to view.

Control panel - mouse icon and change it to eft handed and hit apply if that works its not the mouse - if its an older mouse take it apart and use a pencil eraser to clean the contact points on the mouse

you need to change the tv back to the input your cable box is connected to. Look for a input button on your remote and keep pushing it until it gets to the right input(your cable will come back on). if that doesn't work go into your televisions menu and look for inputs on the menu and go through them till you find the right one. if you have any questions leave a comment on this thread and i will help you out.

easy 12 step to unlock your phone: 1. Hit the menu button 2. Scroll to and select the Manage Connections icon. 3. Select Turn All Connections Off. 4. Press the red End key. 5. Scroll to and select the Settings icon 6. Scroll to and select the Options icon 7. Scroll to and select Advanced Options 8. Scroll to and select SIM Card 9. Enter MEPD Note: When Typing in MEPD the letters will not appear on the screen. This step opens up the personalization on the device. Notice under Network, it will say Active. 10. Enter MEP2 (For "2?, press the ALT key then 2) Note: When Typing in MEP2 the letters will not appear on the screen. Notice the Enter Network MEP code box. 11. Enter the Unlock code (This is a 16 digit code) 12. Press the Trackball or Enter key (once one of these keys is pressed the device should display "Code Accepted.")
The phone has been successfully Subsidy Unlocked is you see in the display next to Network Disabled

*The 16 digit code can be obtained by calling your Mobile Operator's Technical Support and give the representative the IMEI number. In exchange they will give you the Subsidy Unlock Code.
Not all Mobile Operators give away the unlocking code though! alternatively, you can try unlocking providers - check this one here

are you talking about how it shows the letters with numbers like .01, ABC2, DEF3, GHI4, n etc etc.. its like texting on a phone. lets say you are trying to use dogs as the password.. scroll over to the set of letters that has "DEF3" and press the x button on your psp the input screen will show u the letter "d" if u press the x button again it'll show the next letter which will be "e" and so on. so go back to the letter d by pressing x few times. next go to the set of letters MNO6 and press the x button to scroll to "o". notice when u move from one set of letters to the next it'll go to the next space in the series of the word. and now finally to the set of letters GHI4 and press x and u should get the word "dog" in your input display. to input a space hit the triangle button.. to go back hit the square button. hope this helps

select the icon and press the blackberry button next to the trackball. This will give you the option to move the icon. you can apply this to all the icons to set them in the order you want.

i would send it back to the manufacturer. apparently the trackball has a problem and it needs to get fixed. or u can go to a blackberry specialist and tweak the trackball so itll work better

the directional button need to be replaced. www.fixphonenow.com can replace for $55.

I was having issues with my trackball as well....I ordered a new one, it was $12 and that included the shipping from amazon.com.

There is a little aluminum foil piece underneath your ball, and it's probably bent and broke. Pop the ball out and check it out