X830 wont turn on when you hold the on/off button down the keys come on very very dim but thats it! can anyone help

Seems to be a common problem.
You are on the right track with holding down power button.

1. Hold down for 20 secs, Wait 5secs, hold down for up to 10 secs, it may turn on before then.

2. Does the screen have a dim glow, even though there is nothing on it?
Let it discharge itself so the glow is gone, may take some hours.
Plug it into charge for at least 30 mins.
Try to turn it on.

More info here
http://answers.microsoft.com/en-us/windows/forum/windows8_1-performance/why-wont-my-dell-venue-8-pro-windows-tablet-turn/50573983-8cb7-4770-bf5c-478e63ec5cf8

You will need to "reboot"
While pressing down the Nook button (upside down u on the front of the tablet), press the power button on the side. You will need to hold it for couple of seconds.

Hi,

Below are instructions to adjust brightness on HP laptop

1. • 
     Press the "Fn" key with the computer turned on and hold the key.
     
   • 
     Press the "F7" or "F8" key on some HP laptops, which are printed with a small sun icon on the key. The sun icon is filled on the function key for dimming the laptop. The other key is printed with a hollow sun icon for brightening the screen.
     
   • 
     Press the "Fn" and left arrow keys together on some HP laptops to turn down the brightness. The "Fn" and right arrow key will increase brightness. Press and release the right arrow key repeatedly, while holding down "Fn," to decrease the screen brightness slowly, or hold the keys to darken the screen as low as the setting will go.
     
2. 
   
3. For HP Monitors
4. 
   
   • Press and hold the down arrow key on the front panel of the monitor below the screen to turn down the brightness on the external monitor to the lowest setting.
     
     
   • 
     Repeatedly press the down arrow button to dim the monitor gradually.
     
     
   • 
     Press the up arrow key on the monitor to increase brightness.
     
     

Regards,
Rahul

TI calculators have an annoying habit of dimming the screen when the batteries are changed so that it appears as if the calculator isn't turning on. Turn the calculator on (or at least press the ON key). Press and release the 2ND key. Press and hold the Up-arrow key for a few seconds and see whether the screen becomes legible. Does it?

TI calculators have an annoying habit of dimming the screen when the batteries are changed so that it appears as if the calculator isn't turning on. Turn the calculator on (or at least press the ON key). Press and release the 2ND key. Press and hold the Up-arrow key for a few seconds and see whether the screen becomes legible.

If that doesn't do it, then remove one of the four AAA batteries. Press and hold down the ON key. While holding down the ON key, replace the battery.

thats what the $75.00 per hr is for. what happens when the button is pushed? noise? clunk? fuse blows? try turning the key to the ON position, and open the door, get inside, now while holding the door open, hold the window button down, now slam the door, maybe several times, this sometimes will jar it loose. watch the dome light when you push the button down. does it dim slightly? IF there is a short it takes time to find, and that what you pay for....time.

The x-band is the considered a "trash band". It picks up things like automatic doors at supermarkets and such. About every radar detector made has an X band for non-police radar. There is no way to turn this band off on the XRS-757.

Holding down the dim button for 2 seconds turns the V alert on/off
Holding down the city button for 2 seconds turns the Spectra on/off
Holding both city and dim together for 2 seconds turns K and Ku band on/off.

get the codes read,get the throttle body update (free from volvo) done,reset service by holding odometer button done and turn on key till lights come on dash and what approx 5 second release and turn off key ,you may need to do it again until it works

What I do is go on settings, then I go on the sound thing and I can't remeber what else to do as my phone has broken but i think if you look on there it should help you.

or

You hold down the hash key.

hope I've helped you xx

look for a key or button which has a circle with a dot in the middle of it this is the power button
hold it down until you get a response.
Oh make sure the phone is charged first.