My g shock wr20bar watch turned off. Theres nothing at all on the screen. How do i make it work again??

"G-Shock WR20BAR" could mean hundreds of different G-Shock models. If yours is an all digital G-Shock, the answer is fairly simple. When looking at the watch face, the upper left corner button is the "ADJUST" button. Press and hold the ADJUST button for a couple of seconds. You should start to see something flash on the display. Some models will have many options to select in ADJUST mode. To scroll through them, press the MODE button, which is in the lower left corner. You set the hour, minute, seconds, month, date, and year each separately. When you are done, press the ADJUST button again and you'll be back to normal time keeping.

If you want to learn more about your G-Shock, there is something called a "MODULE" inside it that is the brains of the watch. You can find that on the back of the watch, outlined in a rectangle. Usually a 4 digit number. You can download the manual for your watch using that number, if you enter it on a CASIO website:
http://support.casio.com/en/manual/manuallist.php?cid=009

Press the "Adjust" button. It's usually the top-left button, slightly smaller than the rest. When you have successfully pressed the button, one of the numbers on the screen (generally the seconds) should begin to flash.

Choose which number you would like to change (hours, minutes, day, etc.) by using the "Mode" button on the bottom-right to cycle through each option on the main screen. You'll know when you have reached your target position because that number will flash.

Use the top-right button (usually labeled "Start/Stop," or sometimes "Light on/off") to change the number once you have highlighted the position you wish to change. When you have finished making the desired adjustments, press the "Adjust" button again to complete the process.

Use "Adjust" on any screen of your Casio G-Shock watch. To reach the watch's other screens, press "Mode" (bottom-right button). Most G-Shock watches have four screens total, including the main screen. On each screen, use the same process described above to make adjustments to the time (with the exception of the stopwatch screen, which does not keep time.)

click this link for manual
http://ftp.casio.co.jp/pub/world_manual/wat/en/qw3147.pdfhttp://ftp.casio.co.jp/pub/world_manual/wat/en/qw3147.pdf

GO HERE > http://www.gshock.com/support/

A detailed description of this procedure is found in the manual of your watch. You can find the right manual with the module nr. on the back of your watch (4 digit number in a rectangle)

The manual for your watch can be downloaded via the link provided below:

Timepieces Watches

dear sir or madamyou can get instructions from the Casio web site.
heres how: 1. Go to the casio web site "casio.com".
2. Select "support" and the "manuals", watches;
3. Accept terms
4. Select "watch manual archive"
5. Read the number of the back of your watch and enter it into the search box hope this helped!

for people who don't want to do the trouble of looking on the casio webpage here are the steps:
Go to Alm or alarm
press the button in the lower right-hand corner twice
then press the button in the upper left-hand corner to toggle the hourly alarm on an off (it says on or off in the mid top)
here's a link to the casio webpage if u don't understand me http://support.casio.com/storage/en/manual/pdf/EN/009/qw3285.pdf

"wr" is water resistantance and indicates the degree of protection agianst water entering the watch.

press the upper left buton for 5 to 6 seconds the setting of time is apear

If you haven't got instructions on how to do this, you can get
instructions from the Casio web site.

Go to the casio web site "casio.com".

Select "support" and the "manuals",
watches;

Accept terms

Select "watch manual archive"

Read the number of the back of your watch and enter it into the search box

Look for the instruction about daylight saving time (DST).