The target of today’s stress test is a cell phone Siemens A31. This economy version was put on sale in 2006 and soon it caught on among the phones of the same class. We try to test this phone and find its advantages and disadvantages.

Thermal attack

Lower temperature

At first we decided to test the phone in lower temperature. Usually the battery suffers a lot in lower temperature, its power decreases and as a result the time of its work also decreases.

The test was carried out in a freezing chamber in -18 С. At first we put the phone into the chamber for 15 minutes in order to cool it as much as possible. Secondly we made a call from this phone and the calling phone was put back into the chamber. In 30 minutes we stopped calling, then we took the phone from the chamber for examining and continued our experiment.

All in all the phone worked for 48 minutes in calling regime untill the battery was absolutely low. We also need to say that the signal level was a bit deafened by the metal walls of the freezing chamber. The phone consumed more energy to connect to the base station than it does in normal conditions.

However in a low temperature not only the battery lifetime suffers but also the display stops working, it takes approximately a second to change the image on the display. But all the other functions are quite good.

It deserves 7 points.

Higher temperature

Higher temperature test was carried out the following way: the phone was placed under the headlight of 60Wt power and the distance between the phone and the headlight was 10cm. The experiment had 3 stages with the exposure time of 3, 10 and 20 minutes.

3 minute exposure did not have an impact on the phone as its inner parts did not heat till the critical point. After 10 minute exposure the display was overheated and the picture became faded.

After 20 minute exposure the display became absolutely unreadable and the panel melted. However all the other parts (except the display) were good enough and the phone received the calls. In 15 minutes the phone cooled to the room temperature degree and the display color rendering was restored.

According to the order of the stages the phone deserves: 10, 8. and 6 points.

Water and dust test

Steam

60 second steam exposure did not influence the phone badly. Our device received the calls and steam condensate running down the panel was not a big problem. After the exposure was stopped the moisture disappeared quickly from the surface of the phone as the panel was heated  greatly by the hot steam. In 5 minutes the phone was like new and operated well.

It deserves 10 points.

Water

One of the most frequent causes of cell phone damaging is ingress of moisture. TechnoCrash team are going to find out what will happen to a phone dipped into water if this phone does not have any protective means from it. And this is our next test.

After Siemens A31 was dipped into water nothing strange happened. The phone operated well even under the surface. The buttons worked nicely, the signal level was normal and the phone could even receive the calls! All the experiment was recorded on а video camera.

Наd we stopped the experiment the phone failed to identify the SIM card.

All in all, the phone has a good water resistance and it deserves a good mark.

9 points.

Beer

But water is not the only liquid which can damage a phone. In our next experiment the cell phone is going to be sunk in beer.

And again the results are quite good. Almost the same as we had in the experiment with water. But there were some troubles because beer contains salt and other chemically active substances.

There appeared patina under the display. When we took the phone out it started vibrate. After washing and drying we examined our gadget and found out that the buttons “7?, “0? and “#” did not operate but this problem was solved after the phone got dried in some hours.

It deserves 7 points.

Dust

In order to check dust proofness of the phone it was placed into a container full of domestic dust taken from a dust bag. We shook this container with the phone and dust inside for 10 minutes and then looked into to examine the state of the phone. The dust could be easily wiped and blown off the surface of the phone. It was much more difficult to get rid of the dust that stuck between the buttons and in the gaps near the display. Some dust was not wiped off but anyway it was hardly noticed and we could easily press the buttons. There was almost no dust in the slots but there was a lot of under the rear panel. After taking apart the components of the phone we saw much dust under the keyboard and on the board.

It deserves 4 points

Mechanical testing

Quality of materials

The quality of economy cell phone versions leaves much to be desired and our phone is not the exclusion.

The screen glass is made of plastic which is easily scratched. The scratch is quite deep and it is easily noticed in any lighting. That is why we advice not to put the phone with its display down. The panel and the keyboard are stronger than the display. We made a scratch with the same effort as we had done on the display and it was 2 times smaller.

As for the display the phone deserves 6 points
As for the keyboard the phone deserves 7 points

Keyboard

The type of the keyboard that we see in Siemens A31 is used in other cell phones quite often. Practically it never fails in normal working conditions.

The bitterest enemy of this keyboard is water. We also need to say that the buttons of Siemens A31 are big enough and you won’t touch the other buttons with your thumb.

It deserves 8 points

Falling down

Falling on a soft surface

We had 3 stages of testing the phone on its stability in case it falls on the soft surface.

The 1st stage is dropping the phone from the height of 1m, the 2nd from the height of 1,5m and the 3rd from 2m. The surface was fleecy and the height of the nap was 0,4m. We dropped the phone so that it hit the surface with its 6 sides and with each of its corners. One drop for one side and one drop for one corner. All in all there were 30 hits.

The phone easily passed the test of dropping down on the soft surface. But for one time the SIM card was not identified when the phone was dropped down from 2m. After being restarted the phone went on working. No mechanical damage was revealed. During this test the rear panel was quite firm and did not shift.

According to the stages of this experiment the phone gets 10, 10, 9 points.

Falling on a hard surface

The test is almost the same as the previous one but instead of a carpet we used dalles.

The rear panel shifted each time when we dropped the phone from the height of 1m. And it came off in each of the three drops from the height of 2m. But surprisingly the phone itself was quite strong. In spite of the fact that the rear panel often came off the phone did not go off. It operated well, the SIM card, the keyboard – everything worked. Only for one time it did not identify the SIM card.  The damage of the panel was insignificant. There appeared a small gap between the flaps of the panel, small scratches on the glossy line along the phone edges and the spots of the paint which could be hardly seen even if you looked at it very attentively. Then we fastened the rear panel firmly, there was no gap, no unpleasant noise.

Such good testing results can be explained. The phone did not weight much and the lighter the thing is the fewer damages it has.

According to the stages of this experiment the phone gets 9, 8, 8 points.

Squeezing

The panel of the phone bore the load of 20kg on it. No squeak, no crunch was heard. We heard only the sound of the pressed buttons. The rear panel sagged a little but elastic deformation is a normal reaction of the panel.

The phone has a shape of a brick which helps him to distribute the pressure among all its volume. So the phone can bear relatively big loads.

It deserves 8.

Bending

We did not notice any weak points when we bended or squeezed the phone. The board of Siemens A31 is well secured inside a wide frame (the inner part of the panel).

It deserves 8.

Keeping in a pocket

There is a silver coating on the plastic panel of Siemens A31. And as a rule it starts being obliterated because of regular use and because of keeping the phone in a pocket.

In order to estimate the damage of the panel caused by keeping the phone in a pocket we put it into a centrifuge with some small plastic balls inside. Then we revolved the centrifuge at a speed of 10 turns per second (600 turns per minute), the cylinder diameter was 14cm. The test was carried out in 3 stages: 10min, 15min and 20min.

After the 1st stage some worn spots appeared on the panel but it was hardly noticed. After the test was over we could easily see worn spots and scratches. The result of the experiment is on the photo below.

If we continued this experiment the coating of the phone would be rubbed away till we touched the plastic material of which the panel is made.

It deserves 6.

Build quality

The phone has a middle build quality. There is a lot of useless space inside the panel. The components are bulky and not well adjusted to each other. Plenty of dust got inside the phone through the gaps during our stress test. This dust can be seen on the 2nd photo. The board of the phone is also not very well designed. There is a lot of useless space and some components of the board are not adjusted orthogonally.

5 points.

Electric testing

Exceeding voltage supply

In this test we plugged EPU instead of the accumulator battery. The voltage increased to 7 volts. Everything was recorded on a video camera.

As you can judge by this video the cell phone goes off when the voltage reaches 5,6 volts (the 2nd indicator on the gadget). This is a very good feature as the developers of this phone foresaw the situation in which the phone can work with the help of another power supply and not with the help of its own battery.

We also carried out the test on lowering the voltage. The phone went off when the voltage fell to 2.6 volts.

9 points

Minimum voltage for charging

Minimum voltage for charging is 4,4 volts. It is quite good as the full battery has 4,2 volts.

8 points

Charger testing

The charger bears a short circuit without any unpleasant consequences. Even a 2 minute short circuit did not disable the charger.

8 points

Accumulator battery testing

In order to check the quality of the accumulator battery we made a short circuit with the help of the pincers. But the voltage after the short circuit was the same as before it. The matter is that the accumulator battery is protected from short circuits. It prevents the battery from full discharging in case of a short circuit and sometimes saves it from failure.

10 points

Summary

The tested cell phone is quite good and according to the given points in our stress test it is better than many of its competitors which have approximately the same price. But it is far from being the best. Low build quality and as a result not effective protection from dust and moisture. Frost resistance is also a weak point of the phone. The strong point is its stability in case of dropping down.

The impact of the stress test on Siemens A3
The final result is 95,6 points (from possible 127)

Stress test of the cell phone Siemens A31 , 6.2 out of 10 based on 5 ratings