I have a Casio hr100 and the display went out. How do I fix it?

The screen may be defective.

Below is a link to the user manual, you need to look that information up in the manual https://haefuncnumo.files.wordpress.com/2015/09/casio-hr-100tm-user-manual.pdf

I had the same problem with my casio fx-991ES calculator, i tried initializing the calculator by keying in shift9(CLR)3(all)=(yes) but that didn't fix the display,so i opened the calculator and removed the battery for about 5days then put the battery back guess what the display started operating well! no more inverted display or numbers.if initializing the calculator does not fix the problem,take out the battery for some few days then put it back in that should fix the problem.cheers

Let it charge for 24 hours before trying again. Battery may be too weak to light up the display yet.

You should checkout the Omron official website for the manual. This might help you. http://fitness.manualsonline.com/manuals/mfg/omron_healthcare/hr100.html

To get to the general computational mode, press MODE and select 1:COMP.
To change the number display mode to another one, Press SHIFT MODE to enter SetUp. Select NORM or Sci for scientific mode.

after calibrate sensor display numeral are blank

Try pressing the display button.

Flash error problem on casio wk 3300

With a system error there is actually no way to fix this problem at home, it will need to be sent in for service. A system error is internal in the camera and usually is a software issue. The service center's number for Casio is 1-800-706-2534, then option 1.