My professional digital mini scale keeps changing weight without any weights even on what is wrong?

FAQs - Scales

I received my scale and my first weight reading was really wrong. What happened?

The scale may need to be initialized. This process is necessary because the scale was moved during the shipping process. Initializing the scale "re-seats" the internal parts allowing the scale to find the correct "zero." Here is how to initialize your scale:

1. Place the scale back on a hard surface floor.
2. With one foot only, place just enough weight on the scale for the display shows zero's or dashes. Once you see zeros or dashes remove your foot.
3. Wait for the scale to turn off again.
4. Step up onto the scale for a weight.

Or, your scale may be on an uneven surface or on carpet. Be sure to place your scale on a hard, flat surface to get an accurate weighing.

1. Clean the Scale. Make sure that the pocket scale is completely clean. ...
2. Reset Scale to Zero. You want to reset the scale so that it is at zero. ...
3. Find the Calibration Weight. ...
4. Find Nickels for Great Substitute Weights. ...
5. Calibrate. ...
6. Check the Calibration.

hi Sharon.
this link might help you out but not sure.
Thinner scale just keeps flashing 50 0 KG Google Search

You need to send it out to the manufacture and have it recalibrated. Hence the code RCAL.

I’m happy to help further over the phone at https://www.6ya.com/expert/david_c087e4b7d13c0163

You can use the weight of coins to calibrate the scale. Since I don't know where you are here are some examples.
use the newest cleanest ones you can as they do wear and change slightly

http://www.usmint.gov/about_the_mint/?action=coin_specifications
http://www.royalmint.com/discover/uk-coins/coin-design-and-specifications

Are you talking 31 "Stone"? If so, I believe that comes out to 434lbs. You are lucky if your scales can read that high. For testing purposes, remove your shoes or more if you think your right at the upper limit. Or let a slightly lighter friend try it. I assume your talking "Stone" as used in the UK. Are you from there? (I,m in the US, in Florida.) Also, there should be a switch on the bottom of the scale (upper left corner) allowing you to switch between lbs, st and kg. You can try that as well, although the limit should be basically identical. If you tell me more, I can help you more.
(By the way, I weigh 197 lbs right now, that's 14 stone.)

Starting with the unit off. Press the power button and hold down until it starts to cycle through the weights.

mcdevito75 here, There should be some sort of knob or screw near the weight indicator too reset the indicator to zero. Make this adjustment without any weight on the scale.

To totally reset the scale and remove any old data in the users take battery out for 2 hours.

To use the USER functions:
Tap scale to turn it on
When you see "0.0" press
Press SET button. "P-1" will appear and blink
Use UP/DOWN button to select a user number
once desired user number (1-4) appears press SET button to confirm

when 0.0 appears step on scale this will enter your starting weight
press SET to confirm
scale automatically sets a goal weight of 10% below starting. you can raise or lower it by using arrow buttons-Press SET to confirm

Tracking weight
tap, see 0, select user number. Scale displays start weight, then goal weight then 0.0 and you weigh yourself. In the smaller windows it will display last weight and the difference between current and last weight then diff between current and start then diff between current and goal