Scales electronic shopping do it yourself

In detail: do-it-yourself electronic trade scales from a real master for the site my.housecope.com.

Image - DIY electronic shopping scales

Electronic weights, after prolonged use, also fail. Although electronic floor scales are a simple electronic device with few electronic components, it will take a little time to detect breakage and repair the device.

If your electronic weights do not show any signs of life at all, you first need to try to change the battery, as a rule, they are powered by a 3-volt coin-cell battery, and you should not test the scales with a battery from another device, the scales need only fresh and stable ones to work. battery voltage of 3 volts, otherwise some devices may not "start" when the voltage drops to 2.8 volts.
So, if we are convinced that the device does not work with a new battery, we need to disassemble and inspect its insides.

Image - DIY electronic shopping scales

After we have unscrewed all the screws and removed the cover, we need to inspect all visible and accessible connections and installation of radio elements, as well as the integrity of all parts.
It often happens that during operation the wiring going to the board is shaved, or it seems to be still in its place, but already from rotting, you need to lightly try the reliability of their connection.

Image - DIY electronic shopping scales

Found torn wires must be soldered back, and damaged tracks must be restored. The place of the defect is protected, degreased and tinned, a jumper or a large drop of solder is soldered on top. It is advisable to cover the soldering point with a special varnish or simply nail varnish.

Displays in such scales are liquid crystal, as a rule, and are connected to the board either with a ribbon cable, or with a multi-pin conductive "rubber band". It often happens that the rubber band does not adhere well to the board or the display glass, in such cases the image on the display wakes up distorted or incomplete. In such cases, it is necessary to rinse the gum and the board contacts with alcohol, install in place and make sure that the screws fastening the board are reliable, if there is a suspicion of insufficient "tightening" or a loose thread for the screw, you need to press the board against the gum by any means, for this you can, for example, put a small a block of foamy materials such as polystyrene between the board and the back cover, or try to restore the thread density with the help of "moment" glue.

Video (click to play).

All electronic scales have a weight limit that should not be exceeded. When exceeding, as a rule, more than 150-180 kg, the load-bearing elements of the frame structure may bend. Of course, they can be straightened, but such a "repair" will clearly affect the previous accuracy of weight measurements.

In addition, when the weight is increased, one or more measurement sensors, which are located at four corners and are fixed on the load frame, may break. The sensor for measurement is a strain gauge, you can check with a tester, for this we unsolder all four sensors from the board and measure the resistance of the sensors.

Image - DIY electronic shopping scales

In the unloaded state, the resistance of all sensors should be approximately the same, if one of the sensors has large deviations in resistance values, then it is clearly faulty.

It is very difficult to try to repair such a sensor, since it is filled with compound and it is easier to find four new strain gauges or one sensor with identical resistance values ​​from a similar model of scales.

Image - DIY electronic shopping scales

But if you cannot find a new sensor, you can try to carefully pick out the glue (compound) inside there is a copper-colored plate to which three wires are soldered, sometimes it happens that one of them is cut off and it is enough to solder the wires in place and the sensor will be restored.

  • If the scales show only ZERO regardless of the load, then either the load cell is out of order, or there is an open circuit in the circuit from the sensor to the ADC.
  • If the scales do not show anything, then the reason may be either a problem with the power supply (battery) or a break from the board to the “power buttons” which are usually located inside the power frame on two legs of the scales remote from the display.

Image - DIY electronic shopping scales

It often happens that weights fail due to dust and small debris getting into them, as well as when operating them in a humid environment... Perhaps it will be enough in such cases to clean the board and radioelements and dry all the weights.

Sometimes it becomes necessary to calibrate the weights, when replacing load cells or incorrect calibration, for example, when the weights are very false. To do this, you need to press the button to enable them and hold it until you see “CAL” on the display. Then the numerical value of the mass will appear, with the help of which the calibration will be performed. Any object whose weight you know can be used as a reference. Place it on the balance and after a few minutes the display will show “PASS”, then you will need to delete this inscription, turn off the balance, and then turn it on again.

Image - DIY electronic shopping scales

Before repairing the scales, it is necessary to determine the nature of the malfunction. Electronic scales, like many other devices, fail after prolonged use. Being an uncomplicated device, with a minimum number of uncomplicated elements, weights belong to the group of easily repairable devices. This principle can be found in commercial, kitchen, children's and laboratory devices. However, if they are broken, do not display the weight correctly, or do not work at all, in order to find them to be repaired and restore them to working condition, you need to spend a little time. The repair of this technique differs from the restoration of a mechanical balance.

Displays in modern electronic scales are liquid crystal and, as a rule, are connected to the microcircuit either with the help of an internal loop, or with the help of a special conductive "rubber band". It so happens that it is not tightly adjacent to the board or display. In this case, the image on the display will be distorted or incomplete.

In case of problems with the image, you need to rinse the gum, clean the contacts of the microcircuit with alcohol, reinstall everything and check the reliability of the screws with which the board is attached. In case of unreliable fastening, or a thread break from the screw, it is necessary to better attach the board to the elastic band.

Image - DIY electronic shopping scales

To eliminate a malfunction in the balance, it is necessary to replace the battery in it.

All scales operating on electronics, such as those of Tefal or Grodno companies, have a weight limit, which should not be exceeded. If the permissible values ​​are exceeded, as a rule, it is more than 150 kg, the device may deform, the power elements will lose their elasticity. As a result, the device may malfunction.

In addition, the following factors affect the correct operation of the device:

  • If the permissible load is exceeded, the measurement sensor located on the power frame may break;
  • The scales will not work in the event of failure of one or several parts of which the structure itself consists;
  • Often, during operation, the wire leading to the microcircuit breaks.

If, having eliminated these minor misunderstandings, you see that the device still does not work, or shows an error (Err), then you need to take it to the specialists in the service center for more in-depth testing.

All electronic scales operate on the same principle, which means that their main faults are of a similar nature. The scales are designed in such a way that their sensor can go astray at any moment. Then you may notice that they are lying, or the digital electrical panel is just jumping. Why did they go astray, what can be done, and how to fix the situation?

For people who are at least a little familiar with the laws of physics, it will not be difficult to set up an electronic scale on their own. It is enough to carefully follow all troubleshooting procedures.

Image - DIY electronic shopping scales

Adjusting the device is not a complicated procedure, if the scales simply go astray, then it will not require replacement of parts

Self-repair of the scales is also good because in this way you do not need a workshop, and you can save money on calling the master. In addition, in the main, the malfunction turns out to be a trifle, and it will not be too difficult to complete it yourself. It is possible that the battery in your device is simply discharged. Or maybe you need to calibrate.

When it becomes necessary to calibrate the weights, the following should be done:

  • Press the power button;
  • Hold it until the word “CAL” appears on the board;
  • Place an object on the scale, the mass of which you know for sure;
  • When you see the digital value of the mass, adjust the indicator;
  • After the message “PASS” appears on the screen, remove the inscription;
  • Switch the balance off and on again.

Your instrument should now be working properly. If problems persist, look elsewhere for reasons.

Electronic scales work on a different principle than mechanical ones. However, whatever the complexity of the device, the scheme of operation for all electronic devices is the same. It is based on measuring the resistance of a strain gauge. In this regard, the repair of all electronic type scales is carried out according to a similar scheme.

Whatever your home bathroom scale is, the only difference is the electronic filling. All models that determine the biometric parameters of the human body are just a set of resistors with microcircuits. These devices are no different from the primitive Chinese pink flooring devices for teenage girls.

Image - DIY electronic shopping scales

Accurate knowledge of the principle of operation of the floor scale will make it possible to independently carry out minor or major repairs to the device

It is not recommended to undertake repairs of electronic floor scales that are under warranty. Especially if these are expensive and branded products. It is better to take them to a service center, where specialists will conduct high-quality testing, repairs and preventive measures. Those who decide on homemade repairs of electronic floor scales, before disassembling the device, should know their device.

Electronic floor scales usually consist of the following fundamental elements:

  • Load cell;
  • Electronic printed circuit board;
  • Display;
  • Buttons.

Of all this, you will not be able to repair only the display yourself. If it has turned black or all sorts of terrible patterns have appeared on it, then the crystals are destroyed, and it is no longer possible to save it.

If you are convinced that the reason for the breakdown of your scales is not in the batteries, but somewhere much deeper, and are set to repair the device yourself, then first disassemble the device by removing 2 3-volt batteries, and unscrew the bolts on the bottom cover of the case. Then, conduct a visual analysis of the apparatus. Inside the device you will find 4 legs, a battery compartment, a printed circuit board, wires and a screen with buttons. The front and rear legs have a slight difference in the form of a rubber ring and additional contacts with wires.

At the moment of the first pressing on the scales, the rubber ring of the serviceable devices is flattened, the contact is closed, and the scales are turned on. After that, the system waits for another button to close, which means the person's second leg on the scale.

Image - DIY electronic shopping scales

If your scale stops working due to minor troubles, it will recover and you only need to calibrate

Carefully inspect all parts and assess the quality of the electrical connections, the integrity of the electronic board and the serviceability of all parts. If a malfunction is found, determine the nature of the malfunction and proceed with the repair.

Step-by-step instructions for repairing electronic scales:

  • All torn wires must be soldered in place;
  • If the cable that connects the board and the display does not fit tightly, then slightly lift the microcircuit and, more tightly, press it to the display.
  • Using a small piece of wood, install the retainer on the bottom of the scale body;
  • Clean the inside of the device from dust and debris;
  • Align the inner frames if necessary;
  • If the paths of the microcircuit are damaged, then it is necessary to clean the place of the defect with sandpaper, treat the place of damage with a degreasing agent and plunge it. Solder the jumper on top, after which the damaged area should be varnished;
  • In old scales, the ends of the contacts may have worn out, check them and replace if necessary;

If all of the above procedures did not help, then the malfunction is hidden deeper.