Half a screen on digital kitchen timer - Update International Digital Timer, Hour/Minute, 3-1/4 X 2-3/8, W/Clip & Magnet 24 Pie"

It appears to be a built in 'feature'.

• Newly designed with a capacity range from 0.05 oz to 12 lbs (1 gram to 5.4 kg), the Pro II features a built-in countdown kitchen timer with 3 alarm modes (audible beep, blinking LED, or combined).

The new countdown kitchen timer offers an audible beep, blinking LED, or combined audible and visual alarm for the fast-paced chef. The scale's weighing platform is made of durable glass, and the large screen features a new bright LCD with an improved viewing angle.
The Ozeri Pro II Digital Kitchen Scale also features a 3 minute automatic turn-off that yields enough time to make adjustments to measurements before it automatically turns off to conserve battery life. Ships with 2 AAA batteries included, both a calorie and postage guide, and a user manual. Your satisfaction is guaranteed.

Try to track down the user manual, digital timers can be tricky to operate and set properly.

I'm assuming you're referring to OXO's Magnetic Digital Timer model #1127980. The instructions require a CR2032 (coin-type) battery which is accessed by gently prying the battery cover off with a coin. You can download the instruction booklet here:

http://www.oxo.com/download/1183_gg_1127980_booklet.pdf

How do I set the timer on Regis JVT3-16D Digital timer?

The digital timer needs to be set to the manual mode for the oven to work. If the timer is lit then play with it until it goes back to manual. Turn the oven on and keep an eye on the indicator light. When it lights the timer is on manual. If the timer is out and not working you may need to get a new digital timer. This is a problem which occurs from time to time.

Use the resolution button on the top of the camera by the LCD display. One button is for selecting Flash. One button is for the self-timer. The middle button is for resolution. Press the button repeatedly to cycle through the options. One Star for Basic. Two Stars for Normal. Three Stars for Fine (High Quality). HALF means half the amount of data, perfect for e-mails and screen savers. FULL means full data, perfect for prints.

Use the resolution button on the top of the camera by the LCD display. One button is for selecting Flash. One button is for the self-timer. The middle button is for resolution. Press the button repeatedly to cycle through the options. One Star for Basic. Two Stars for Normal. Three Stars for Fine (High Quality). HALF means half the amount of data, perfect for e-mails and screen savers. FULL means full data, perfect for prints.

Use the resolution button on the top of the camera by the LCD display. One button is for selecting Flash. One button is for the self-timer. The middle button is for resolution. Press the button repeatedly to cycle through the options. One Star for Basic. Two Stars for Normal. Three Stars for Fine (High Quality). HALF means half the amount of data, perfect for e-mails and screen savers. FULL means full data, perfect for prints.

Use the resolution button on the top of the camera by the LCD display. One button is for selecting Flash. One button is for the self-timer. The middle button is for resolution. Press the button repeatedly to cycle through the options. One Star for Basic. Two Stars for Normal. Three Stars for Fine (High Quality). HALF means half the amount of data, perfect for e-mails and screen savers. FULL means full data, perfect for prints.