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是否已经在后期制造过程中解决了呢？
求内幕。

Defective Flagships. The Nokia N8 and Nokia C7 Dying around the Globe

Unfortunately, manufacturers' attempts to lower productions costs as well as their pushing new models to the market are made at the expense of decreasing testing periods. This can result into a large amount of phone defects that reveal themselves as early as within the first few months of ownership and can become a curse of a particular model. It is quite disappointing to have to take one's newly bought phone to a service center and then to wait several weeks for it to get repaired. It hurts even more to get the device from the service and have to send it back.

Mobile-Review.com has done a lot of work investigating mass phone defects and published a lot of materials dedicated to the nature of such defects and their causes. Our resource is the only one constantly paying attention to this delicate issue despite all fury and anger that each and every manufacturer welcomes such discussion with. We have an excellent article about where phone defects come from and I highly recommend you to take a look at it. We also led our own investigation of the speaker defect in the Nokia 5800 (we were able to discover it before the company itself and provided a complete coverage of it; the defect was acknowledged by Nokia eventually), defects in the Nokia N76 as well as in some products from other manufacturers. Today, we are going to talk about Nokia's flagship, the Nokia N8, and its fellow device, the Nokia C7. In our opinion, these phones have principle defects, which Nokia, trying to preserve its reputation, refuses to acknowledge.

Some Nokia C7 Tests, or a few Phone Deaths

I learned about the Nokia C7 defect accidentally. For a test of some carrier service, I needed Symbian^3 devices and the Nokia N8 and Nokia C7 were the only models available on the market. Since I needed as many as five phones for the test purposes and didn't feel like spending a fortune on that, the logical decision was to go with the cheaper Nokia C7 (I wasn't going to use the camera anyway). The units were bought at an official Nokia retail store and as such were part of a regular shipment for Russia.

I didn't have a slightest problem with either of the phones during the first week but later, I noticed one of them reboot spontaneously. After some time, that would happen every once in a while, until it refused to boot up at all. Well, what can I say? Such things happen and I didn't get suspicious at once. Phones break down sometimes, just like any other electronic device. It is disappointing when a new device malfunctions and it doesn't happen often but is still possible. One day later, another Nokia C7 failed. By the end of the tenth day, 3 of my phones had been dead and one was showing the symptoms (e.g. rebooting and overheating). I believe that there is more to such behavior than coincidence and such defect ratio can only be explained by some principle manufacturing defect or design flaw. That is why I decided to inquire into the situation and my first stop was a service center front desk where the dead units were taken.

In the Service Center, or about the Nokia N8 Dying around the Globe

At the front desk, I got into a conversation with an engineer (I didn't tell him who I was or what my professional interests were) who told me that the Nokia C7 wasn't a frequent guest there, albeit they did get a few units for repair. On the other hand, the Nokia N8 turned out to be much more "popular" than one would expect a new model to be. Obviously, the discussion made me interested and back to the office, I spent a few hours browsing through various international forums trying to learn more about the Nokia N8 deaths.

A quick search on the Web resulted in over a hundred thousand citations worldwide. This number doesn't map one to one into the number of defective units, of course, but it is a good indication of the problem being widely known and discussed. Here I would like to remind you that the sales began on September 30 and gained momentum at the beginning of October. Below you can find links to some threads on the official Nokia website:

Nokia N8-00 keeps turning off
My Nokia N8 is dead, can't turn on and can't charging

One thing appears to be true about all Nokia N8 deaths so far – i.e. the phone simply won't start up. It just turns into a lifeless brick. Occasional spontaneous rebooting is reported to precede that. The majority of reports are coming from Asia, not from Europe. It looks like any unit, regardless of when and where it was bought, could be affected, though.

The easiest way to find out whether or not the manufacturer is aware of the problem is to learn if the official service centers have received the corresponding service bulletin from Nokia. Such document should contain the description of the problem and ways to solve it. It is a must for the service centers as it entitles the owners to a replacement of their defective units or a full replacement of its electronics board. Without the service bulletin, there is no way around the usual testing routine. As of November 21, 2010, the service centers have not received any instructions about the Nokia N8 or Nokia C7 problems. That is, no service bulletin has been issued. I'm running a bit ahead of myself, though.

While instigating the sudden deaths of the Nokia N8 I started to accumulate some information. Since we do not have access to the worldwide Nokia N8 sales data, we will have to consider the case of Russia to get an estimate of the number of defective units. With roughly 2000 units being sold every week, Nokia isn't able to satisfy the demand and the phone appears to be in the deficit (according to a report from Mobile Research Group, which goes in line with the results of a retail panel carried out by GfK RUS).

A quick survey of the service centers and retail chains indicates that approximately 400 and 800 units of the Nokia N8 were taken for repair in October and November, respectively (as of November 18; not all service centers covered; regions not covered). I would like to point out that some units haven't made it to the service centers yet but are still being processed by the retail.

As of October 2010, the defect ratio is estimated to be around 5 percentage points and is going to double by the end of this month. So, how big is the problem?

The service centers are facing an abnormally high failure rate for a new model, something that has proved to be indicative of an innate flaw (e.g. a component problem, assembly or design issue). Since the defect does not reveal its face at once and it all may depend on the usage scenario after all, the number of defective units is only going to increase over time. A defective unit can last for as long as a couple of years before it breaks down or die in just a few days if used intensively. It is a lottery. And even if the former scenario turned out to be true, it wouldn't mean that the phone hadn't been defective from the very beginning. One's usage habits may have a great impact on whether the defect manifests itself or not.

Usually, a phone gets returned during the first month because the owner doesn't like it in general or is disappointed with some particular feature but not because it won't turn on. For example, when the Apple iPhone made it officially to Russia, the return rate was about 6 per cent. But it was direct returns from those who simply realized that it wasn't their device. There were no hardware problems there.

As of this writing, no service center has been notified by Nokia about the existence of Nokia N8/C7 problems unfortunately. Therefore, our task was even more difficult, that is, to find the cause of the problems, and the search process turned out to be quite exciting.

In search of problems: Nokia N8 and C7

What do these models have in common? The first look tells us that Symbian^3 is the main unified feature. How an OS can make the model switch off and "die"? It is theoretically possible, but you cannot prove it in real life as all Symbian^3 smartphones should suffer from the same plight then. We cannot discard this fact, but it cannot be the most important one as recent changes in Symbian^3 are not dramatic enough.

Another common factor is the board where all components are located. A small board has many layers and the manufacturer declined the use of the compound (a type of resin to cover the perimeter of the board for better vibration resistance and connection of layers). This decision saves costs and while the use of the compound takes seconds on the conveyor it increases the price and makes the conveyor less productive. The disadvantage is obvious as the physical resistance of the board goes down.

We could not find problems in components and it was difficult as we lacked the necessary tools. That is why I will provide a hypothesis prepared together with several service engineers, who boast many years of experience in the area. For obvious reasons they prefer to stay anonymous and not lose their jobs.

The problem of Nokia N8/C7 looks this way – the handset reboots and after some time it stops switching on. It can be resurrected by a "mild" reboot (press and hold Power key for 8 seconds). Soon the phone stops operating anyway. Service software and rewriting of memory may help, but only once and the phone "dies" forever.

Some people believe that the problem is caused by the installation of additional software, which leads to reboots. This connection really exists, but it has nothing to do with the quality of apps and is rather predetermined by the nature of problems. Smaller board has a less effective heat removing and the heating of the processor and other components leads to emergency reboots. This is one of the reasons for the problem. Several users managed to start the phone by putting it in the fridge first. You cannot solve the issue entirely this way, but we get a curious feedback. The processor is not the main culprit. It can switch off due to overheating, but it is caused by the construction itself and the mode of exploitation (additional apps, non-converted video, etc.).

Reboots due to overheating should not destroy the phone. When the temperature of the processor goes down it should be ready to perform quite soon. Unfortunately, it does not happen and the handset becomes useless afterwards.

EEPROM flash memory is to blame. It is used to store data and all disabled models had damaged EEPROM, several units of which had false information recorded there. It could happen when the power is broken due to overheating, but it is not realistic as the period of time is too short. It is more probable that one of board contacts was lost and false information was recorded instead of what was on its way through the bus. Lose one contact and all transferred information is turned into rubbish. Why contacts can be lost?

We have to mention that similar to other manufacturers Nokia moved to green soldering without the use of lead. Soldering machines now operate in a limited temperature range. Sometimes the soldering looks fine, but some elements are misplaced in respect to their board positioning. Usually, it doesn't matter as the board is hard enough and has not many layers. Nokia N8/C7 has a multilayered board without the compound and during the heating (the processor heats up more than in previous models) the board can be distorted. These distortions are minimal, but are enough to lose one contact on the bus leading to EEPROM. Bear in mind that this is only the most probable suggestion we could come up with.

To test this version I put several Nokia N8 in a temperature chamber (+ 40 C) and started video playback (DVDRip) in the cycle. Two models out of three had problems. One had SIM card slot disconnected (card not found) – its functionality was restored without external interference 24 hours after it was taken out of the chamber. The other model had reboots, while the phone 3 worked well during this testing day.

There are numerous complaints in Asia where the temperatures are higher and it is another circumstantial evidence to confirm our hypothesis. We can surely declare that the problem is associated with temperature. You can claim that a particular component failed due to higher temperature levels, but we found no facts to back up this idea.

Nokia confirms Nokia N8 problems or PR games

Any manufacturer may experience problems with any device. The main point here is the reaction of a company and its attempts to deal with the issue and satisfy the customers as much as possible. While preparing the article we communicated with Nokia partners, retailers and service centers. I have not hidden the fact that I was writing this material. Nokia took it for some PR game and decided to join in. The problem itself was ignored. As of November 17 Nokia had no information about the mass defects of Nokia N8. They turned to their partners for appropriate information (number of returns, handsets in service, etc.) only after we started our investigation. In terms of PR I approve the desire of Nokia to soften the effect of the news and make our discovery of defects in its flagship model look invalid. For example, AllNokia.ru claimed that Nokia N8 has no defects and these were the fantasies of Eldar Murtazin. Readers were encouraged to take part in a poll. Allnokia.ru is supported by Nokia in an indirect way (taking into account the number of warez, examples of software alterations and unlocking of handsets, this support cannot be official) and functions as an information outpost in Russia. I think the results of the poll will be treated as fair. Interestingly, out of 649 persons who voted, 50 had to replace their models (7%). These figures coincide with what we have mentioned above. This is just the beginning of problems as this trend will be gaining momentum in future.

When I published first data on the number of defected models Nokia Conversation blog placed a video where the Executive Vice President of Nokia Niklas Savander discussed Nokia N8 quality issues with another employee of Nokia.

In the video the second representative of Nokia confirms that Nokia admits defects in N8, but it is related only to a limited number of handsets. He adds that the defects are identical on all markets. The main thing is he says that several Nokia N8 suffered at the conveyer, which resulted in power issues and these models can be exchanged in Nokia service centers. He claims that as of the day of the video the issue has been solved and all new N8 are up to the mark.

I am glad that Nokia acknowledged Nokia N8 defects, but sadly they hide similar defects in Nokia C7. Probably Nokia think that as its sales have just started they will have time to solve the issue before it becomes know to the public. It's risky. There are some controversial issues - Nokia hasn't issued the service bulletin for Nokia N8 and all service centers follow the standard procedure. They resurrect handsets and return them to clients, but they "die" at the end nonetheless. One of clients posted an angry message on Nokia forum and you can see it below. The phone switched off on November 1, he had it returned from the service centre 16 days after, but the next day it switched off again. This story is quite sad.

Nokia shops in Russia advise clients with such problems not to install additional software and "carefully observe the phone". It is not a solution, but Nokia hasn't decided how to exchange the phones. According to engineers you cannot repair such phones as they require the replacement of boards.

Roadmap for customers or what happens next

If your phone (Nokia N8/C7) started rebooting you are not lucky and the handset has defects. With time EEPROM will be full of false info and the phone will stop switching on. Within 2 weeks from the purchase you can return the handset to the seller and get a refund. Alternatively, you can go to the service centre, but at the moment it has no point (new boards are unavailable and new phones are not offered for exchange). "Repair" will not help in the long run and you will have to replace the handset.

When the situation will change? According to the top manager the necessary manufacturing changes have been effected, but improved phones will go on sale by the end of January or the beginning of February. They will be manufactured at the end of November or in December of 2010. Whether Nokia managed to solve the issue remains to be seen, but as of December 2010 Nokia will start producing handsets free of defects. Delivery takes time, so do not expect to see them in shops until February.

To those who like the model and cannot find a better replacement I recommend to back up all data, and wait when the phone is replaced or "repaired". The level of defects for the first two months of sales is abnormally high, so almost all phones are at risk. According to feedback that we have these are different handsets, which have nothing in common but the fact they are Nokia N8 or C7. These are the signs of mass defects, which is clear from discussions in various media.

Customers planning to buy Nokia N8 or Nokia C7 should wait until February or March of 2011 or take risks. If you are lucky or ready to wait until your phone is replaced or repaired go ahead.

We will have an open eye for the story around defects in Nokia N8 and keep you informed. If you have anything to add go to our forum.


根据作者的观点，N8、C7的故障原因，是由于主板的材料运用和制造方面存在问题，再加上焊接工艺的缺陷造成EPROM BUS与主板之间的一个焊点很容易由于主板受到CPU发热及环境温度的影响导致轻微变形而造成开焊，以致ROM被持续写入错误数据，从而造成系统崩溃进乃至无法启动... 诺基亚已计划在后续生产中进行了相应的处理以彻底解决问题...

本人分析：Nokia官方声明中表示部分N8的电源管理模块存在问题，与上述观点并不相符，而且无法解释为何会先出现频繁无故重启的现象之后才会无法开机（电源管理模块有问题的话，问题会立即显现出来，而不是逐步恶化直到变砖）... 所以我宁愿接受作者的看法。

本人结论：目前N8和C7所出现的故障，可能不是简单的通过刷机就可以解决的（这一点貌似也有证据证明，此帖供参考：http://www.nokiabbs.com/thread-953753-1-1.html），而需要通过更换主板的方式彻底排除... 至于目前正准备出手购买N8或C7的朋友，建议再等等，因为改进后的产品才刚刚开始生产，到达销售地可能还需要一段时间，实在没有为提前一两个月玩到新机而冒巨大风险的必要...

[ 本帖最后由 henryzyl 于 2011-4-8 18:21 编辑 ]