Stress test of the cell phone Nokia E71


In this review we are going to tell you about the results of the stress test of Nokia E71, a smartphone with a QWERTY keyboard. The phone looks like a business class device and this is really so. Some parts of the handset are made of metal. The gadget has a LI-pol battery with 1500 мАh capacity.

The delivery set includes a midget charger, USB-cable, handsfree, manual and a CD (pic.1, 2). At first look the phone can easily pass all the tests that we prepared (pic.3, 4). Let’s prove it.
Results

Рис. 2. Комплект поставки

Pic.2. Delivery set

Рис. 3. Лицевая сторона Nokia E71

Pic.3. Front side

Рис. 4. Тыльная сторона Nokia E71

Pic.4. Back side

1. Stress test of the Nokia E71. Stage 1 – Ability to withstand light shocks

1.1 Drop-down

We started testing the Nokia E71 with the drop-down test as usual. We sequentially dropped the phone down onto each face, edge and corner from 1m on the carpet (video 1) and from 30cm on the ceramic tiles (video 2). Nokia E71 easily survived. No damage. Nothing shifted or fell off.

Video 1. Drop-down on the carpet from 1m

The grade is 30 from 30 possible.

Video2. Drop-down on the tiles from 30 cm

The grade is 30 from 30 possible.

1.2 Ability to withstand squeezing

One of the most frequent problems that a mobile phone may have is squeezing. We found out what would happen to the Nokia E71 if we put it under a 3kg load. Actually we put the gadget on a table and then put a 3kg plank on it (pic.5). We heard only the sound produced by the keys of the phone. No damage – full survival.

Рис. 5. Телефон под давлением 3 кг

Pic.5. Nokia E71 under the 3kg plank

The grade is 24 from 24 possible.

1.3 Bend test

It must be noticed that when a mobile phone is squeezed it does not always lie on a flat surface as in the previous test. As a rule a cell phone is more likely to be bended than squeezed. Bending can damage not only the design of the gadget but also the inner parts. It can crack the display or damage the board.

Actually we put the Nokia E71 on the two planks so that each edge of the phone lay on a plank. Then we hitched a rope with 1kg load over the phone (pic.6). It was not enough to make even a millimeter bend.

Рис. 6. Тест на перегиб

Pic.6. Bend test

The grade is 24 from 24 possible.

1.4 Deterioration

We put the Nokia E71 into a cylinder of a centrifuge together with some keys, coins and plastic balls. The centrifuge rotated the cylinder for 5 min (video 3). In the result some scuffs appeared on the plastic parts of the handset (pic.7) but the matted cover of the phone made it hardly noticeable. Some droplets also appeared on the display but we could see it only in the bright light. The metal parts were like new

Video 3. Rotation of the centrifuge

Рис. 7. Потертости пластмассовой вставки

Pic.7. Scuffs on the metallic part of the phone

The grade is 15 from 15 possible.

1.5 Quality of the material of which the phone is made

The look of your mobile phone may change greatly in the course of time. It depends a lot on the quality of the material of which the phone is made. We decided to check it by scratching the screen and the back cover of the Nokia E71 with a nail at the force of 100g (video 4, 5). Fortunately we could make a scratch neither on the screen nor at the back.

Video4. Scratching the display

Video5. Scratching the back cover

The display gets 15 from 15 possible.
The back cover gets 15 from 15 possible.

1.6 Hot temperature

We discovered the reaction of the Nokia N97 to a hot temperature by putting it into a metallic container with a 40wt lamp installed 5cm far from the phone. The lamp was heating the device for 3min. (video 6). When we took the N97 out it worked perfectly, we found no damage.

Video 6. Hot temperature test

The grade is 12 from 12 possible.

1.7 Dust resistance test

Usually the handsets which are made of metal have large gaps between their metallic panels. These gaps let in a lot of dust which can break a phone. In order to check the Nokia N97 dust resistance we put it inside a box which was full of dust and shook it for 2min.

You can see the phone after this test at pic.8. There was not much dust under the back cover (pic.9) and there was no dust at all inside the port because it was protected by a peg (pic.10). We easily cleaned the Nokia E71 from dust. The keys worked perfectly without any noise.

Рис. 8. Вид передней стороны аппарата после теста

Pic.8. The face of the phone after the test

Рис. 9. Пыль под задней крышкой

Pic.9. Dust under the back cover

Рис. 10. Разъем остался почти чистым

Pic.10. No dust inside the port

The grade is 15 from 15 possible.

1.8 Communication quality

Communication quality test is a very important challenge for any cell phone. We put the handset into a shielded box with 40×50mm hole (video 7). The indicator showed that the signal reception fell by 1 point. But the phone received all the calls with no problem.

Video 7. Communication quality test

The grade is 15 from 15 possible.

All in all for the 1st stage of the stress test the Nokia N97 got 192 points from possible 192.

2. Stress test of the Nokia E71. Stage 2 – Tougher conditions

2.1 Drop-down

We increased the height of the drop-down on the carpet from 1m to 1,5m and we also dropped it from 50cm on the tiles. When it hit the carpet the back cover fell off. The catch lock deformed because of this fall so that the back cover was not closely attached to the handset (pic.11). But we mended the catch lock and everything was fine again. The Nokia E71 survived. Drop-down on the tiles did not cause damage at all.

Video 8. Drop-down on the carpet from 1,5 m

The grade for the drop-down on the carpet is 20 from possible 30.

Video 9. Drop-down on the tiles from 50 cm

Рис. 11. Крышка неплотно прилегает к корпусу

Pic.11 The back cover was not closely attached to the handset

The grade for the drop-down on the tiles is 30 from possible 30.

2.2 Ability to withstand squeezing

The camera took most of the load because it protruded above the back side of the handset. But the 10kg load did not cause any damage. The phone passed the test successfully.

The grade is 24 from 24 possible

2.3 Bend test

We increased the weight of the load on the rope from 1kg to 5kg and saw no bend again. Surprisingly it was not enough to make a bend or damage the handset.

The grade is 24 from 24 possible

2.4 Deterioration

We increased the time of this experiment to 10min. This time we saw a few more small scuffs and scratches on the phone. The cover of the handset was damaged (pic.12). More droplets appeared on the display (pic.13). We must also notice that the Nokia lost its back cover when it was inside the rotating cylinder. It never happened to the other cell phones that we had ever tested.

Рис. 12. Повреждения на ребре корпуса

Pic.12 The edge of the handset is damaged

Рис. 13. Потертости на дисплее

Pic.13 Scuffs on the display

The grade is 15 from 15 possible.

2.5 Quality of the material which the phone is made of

At this stage of the experiment we increased the force of scratching the screen to 300g. We were really surprised when we saw no scratch neither on the display nor at the back.

The display gets 15 from 15 possible.

The back cover gets 15 from 15 possible.

2.6 Cold temperature

People often complain that their batteries in the cell phones discharge too fast. Nokia E71 has a LI-pol (lithium polymer) battery which much better than a Li–ion. We checked the performance of this battery in -15° C. The test lasted for 2 hours. All this time the phone was in a speaking mode (pic14).

When the time was over we examined the Nokia E71 (video10). The battery lowered only by 1 point which is a good result because the level of signal reception is much worse in the freezer than outside and the battery consumed more energy in the freezer than it would do in the street for example. The display hung up sometimes and the keys became a bit rigid but worked well. The metallic handset was frozen and it was cold and unpleasant to take it by hands.

Рис. 14. Телефон в коробке со льдом

Pic.14. The E71 in the freezer

Video 10. The Nokia after the test in the freezer

The grade is 18 from 18 possible

2.7 High temperature

We increased the time of the test to 5min. (video11). When the time was over we took the phone out and examined it. The display color rendering was as good as before. Neither the handset nor the keys deformed.

Video 11 High temperature test

The grade is 12 from 12 possible.

2.8 Water resistance test

Everybody knows that water damages electrical appliances and a mobile phone is not an exception. People sometimes accidentally drop their handsets into water. But we did it on purpose. We checked how the Nokia E71 could survive after being under water for a second (video 12).

At the pic.15 you can see the phone after the immersion. A lot of water penetrated under the battery and reached the board (pic.16). It made a corrosion effect on the conducting parts of the board. The peg protected the USB-port successfully. We saw no water inside the port. The Nokia E71 operated well after this test.

After this experiment we dried the phone with warm air for an hour. Then we examined it once again and found out that the key “3” did not work. We decided to continue the test because this break was insignificant.

Video 12. Immersion in water for a sec

Рис. 15. Аппарат после теста
Рис. 15. Аппарат после теста
Рис. 16. Проникновение жидкости под батарею
Рис. 16. Проникновение жидкости под батарею
Рис. 17. Разъемы остались почти сухими

Pic.17. No water inside the port

The grade is 20 from 30 possible.

2.9 Dust resistance test

At the 2nd stage we increased the time of this test to 5min. The result was the same as in the previous dust resistance test. The only difference was the USB-port. There were many small pieces of dust (pic.18). We also spent a lot of time clean the dust out the gaps between the keys – there was much dust and mud. There was as much dust under the back cover as there was in the previous dust resistance test. Though the ear-microphone jack and the charger jack are not protected by pegs there was almost no dust inside.

Рис. 18. Пыль в разъеме

Pic.18 Dust inside the USB-port

The grade is 12 from 12 possible

2.10 Communication quality

In order to create worse conditions for the Nokia E71 signal reception we decreased the diameter of the hole in the shielded box to 20×20mm (video 13). During the test the signal reception  lowered to 0. The phone did not receive any call.

Video. 13 Communication quality test

The grade is 5 from 15 possible.

All in all for the 2nd stage of the stress test the Nokia E71 gets 210 points from possible 240.

3. Stress test of the Nokia E71. Stage 3 -  The toughest conditions

3.1 Drop-down

This time we dropped the phone down on the carpet from 1,5m to 2m and from 1m on the tiles (video 15). Though the back cover did not fell off the catch lock deformed and the back cover was not closely attached to the handset again.

Drop-down on the tiles was fatal. After the last attempt the phone switched off and the push-button did not work. We did not even hear the click when we pressed it. It was impossible to switch the phone on. Probably this button was broken when the E71 hit the tiles by its upper part.

Video. 14 Drop-down on the carpet from 2m. The grade is 30 from 30 possible

Video. 15 Drop-down on the tiles from 1m. The grade is 0 from 30 possible

3.2 Squeezing

We increased the weight of the load on the rope to 20kg. The phone fully survived. Neither metallic nor plastic parts of the phone were damaged.

The grade is 24 from 24 possible.

3.3 Bend test

When we tested the Nokia 6500 slide we told that it was great to see only 1mm bend when the load on the rope was 10kg. However our Nokia E71 showed even better result – there was no bend at all (pic.19) due to its metallic front panel and a hard and rigid back cover.

Рис. 19. Перегиба аппарата не было вовсе

Pic.19 No bend

The grade is 24 from 24 possible

3.4 Deterioration

After being inside the rotating cylinder of the centrifuge for 20min. the phone was damaged significantly. There appeared more small scratches and dents on the plastic parts of the handset. The edged suffered a lot (pic.20). There were more droplets on the display (pic.21). But the metallic cover was like new. We could hardly see even small scratches on it.

Рис. 20. Повреждения на ребре корпуса

Pic.20. Damage of the edge of the handset

Рис. 21. Потертости на экране

Pic.21. Scuffs on the display

The grade is 15 from 15 possible

3.5 Quality of the material of which the phone is made

The maximum force of scratching was 600g. The back cover did not change at all, we failed to make a scratch on it. But we managed to make a not very deep but noticeable scratch on the display (video16, pic.23).

Video 16. Making a  scratch on the display

10 points (from 15 possible) for the display
15 points (from 15 possible) for the back cover

3.6 High temperature

We did not carry out this test because we could not switch on the cell phone

The grade is 0 from 12 possible.

3.7 Water resistance test

May be 1 second is not enough for water to penetrate inside every gap of a cell phone. But what about 20 seconds (video 17).

When the Nokia E71 was under water it displayed its connection to the handsfree. Evidently water penetrated inside the ear-microphone jack. The result was the same as in the previous water resistance test. The USB-port was dry, the battery was wet. A lot of water penetrated under the battery.

When we dried the Nokia the interior of the camera glass fogged up. It proved the fact that the water penetrated deep inside the phone (pic.24).

Video 17. Immersion in water for 20sec

Pic.23. Fogging up of the camera glass

The grade is 30 from 30 possible.

3.8 Immersion in beer

We did not carry out this test because we could not switch on the cell phone

The grade is 0 from 9 possible.

3.9 Dust resistance test

We increased the time of this test to 10min. This time there was a lot of dust under the back cover, little dust inside the USB-port (pic.25). We easily got rid of the dust. However the loudspeaker sounded with a rhonchus because dust penetrated inside it. The polyphonic loudspeaker had a good sound quality. We could not clean only the keyboard because dust and mud penetrated into the little gaps between the keys.

Pic 24. Dust under the back cover

The grade is 10 from 15 possible

3.10 The keyboard

At first we noticed that the side keys made loud noise and we could easily press them into the handset. We took the phone apart and found out that the keys had a plastic mount which is easily damaged by any liquid. If the water reached the mount the keys would be broken.

The QWERTY keyboard is not very comfortable to use. After all our tests the keyboard became slack. We do not mean that it did not work but it irritated us.

The push-button of the Nokia also has a plastic mount. It is installed in the board face and even if you push it hard it won’t be broken.

The grade is 10 from 15 possible.

3.11 Communication quality

we decreased the diameter of the hole in the shielded box to 20×20mm (video 18). During the test the signal reception was 0. The phone did not receive any call.

Video 18. Communication quality test

The grade is 5 from 15 possible

3.12 Electric overloads

We did not carry out this test because we could not switch on the cell phone. It was broken.

The charger gets 0 points from 15 possible.
The battery gets (for the short circuit) 0 points from 15 possible.
Min. and max. power supply – 0 points from 15 possible.
The grade for the overcharging test is 0 from possible 15.

3.13 Disassembling, build quality

After all the tests we took the Nokia N71 apart (pic.26) because we wanted to know why the push-button and the key “3” stopped working. The build quality of the gadget was also important. We have to admit that it was not easy to take the handset apart. Evidently the “Nokia” engineers did not think much about the possibility of repairing this cell phone. For the same reason, perhaps, all the shields of the board were stationary (pic.27). The board itself is as large as the handset. There was much empty space between the components of the board. It was also a failure to place the battery on the board. It makes it unprotected from dust and liquid.

The QWERTY keyboard is quite simply designed (pic.28). The copper pads are covered by the adhesive substrate without any carbon sputtering. You can see such a peculiarity in some other “Nokia” cell phones. We saw some water spots inside the mechanism of the key “3”. When we dried the handset this key started to work again.

At last we got to know the reason of the push-button failure (pic.29). The metallic plate of this button was deformed because of the drop-down test.

Рис. 25. Телефон в разобранном виде

Pic.25. The Nokia E71 taken apart

Рис. 26. Плата
Рис. 27. Клавиатура со снятой подложкой
Pic.27. The QWERTY keyboard with the mount taken off
Рис. 28. Поврежденная кнопка

Pic.28. The broken button

The grade is 20 from 30 possible

All in all for the 3rd stage of the stress test the Nokia E71 gets 201 points from possible 351.


Conclusion

The result of this stress test was not good. But it was not too bad because the Nokia N71 passed the 1st stage of our experiment very well. The break of the push-button is an exception rather than a rule.

The fact that the handset is made of metal is a disadvantage which is revealed in extreme temperatures. At first we thought that the back cover is closely attached to the handset. But during the drop-down tests it often fell off and the catch lock deformed.

The real advantage of the gadget is its battery which can work perfectly in cold weather.

The lok of the Nokia E71 after the stress test (piс.30,31).

Рис. 29. Вид лицевой стороны после теста

Pic.29 The front side of the handset after the test

Рис. 30. Вид задней панели после теста

Pic.30 The back side of the handset after the test

All in all the phone gets 603 points from possible 783.

According to 100-rating scale the Nokia E71 gets 77 points.

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Stress test of the cell phone Nokia E71, 10.0 out of 10 based on 5 ratings
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