Here I found an interesting article, I decided to share ...
Handheld computer is convenient and useful. However, in the lives of many owners of these devices, sooner or later the moment comes when the machine breaks down ... So, about breakdowns. Some are associated with careless handling, others - with imperfect design. Knowing the weak points of specific models, you can avoid some problems, but you cannot completely eliminate the risk of damage to the PDA ...
will be recognized as a warranty, the owner will have a long wait: the CCP will be sent for repair to the factory (and the chances of getting a service center for the duration of the repair defective PDAs are small). Even branded service centers (especially in regions) basically send the device to the manufacturer (for example, if you have a HP iPAQ, in most cases, repair is performed only at a factory in the Netherlands and four to five weeks spent on it). If the damage is caused by, for example, the fall of the CCP, the warranty repairs, of course, will be denied. You will be offered a paid repair, but it is likely that the cost would be only slightly less than the price of a new model.
At the same time, many faults can be rectified by yourself, just need some experience in soldering and micro-miniature devices. Of course, this is an extreme measure, but sometimes there is no alternative: in the regions to appeal to the service center to the user may need to overcome a few hundred kilometers. And when you have nothing to lose, and the price of the repair is comparable to buying a new vehicle, we can only try to "revive" the damaged PDA. This article discusses typical faults iPAQ Pocket PC family of HP, but many tips can be used in the repair of other manufacturers' devices.
Attention! The article is written for all PDA owners, however, not any repair can be carried out independently. Replacing some components requires appropriate equipment and electronic equipment repair experience. The author and the editors are not responsible if the PDA or its owner suffers any damage during attempts at self-repair. But we hope that this short review will help to вЂњbring back to lifeвЂќ the faulty devices.
What you need to know, be able and have
In its device, the PDA is close to a mobile phone, therefore, in the absence of a specialist in repairing pocket computers, it is quite likely that the master working with mobile phones will cope with it. In most cases, it is better to contact a specialist, unqualified intervention can only worsen the situation, although some parts of the body (and not only) may well be replaced by the owner on their own, without using a soldering iron.
Another problem - parts. Practice shows that the best source of spare components for repair of the CPC - the same broken phones (they act as "donor"). Something that can be found or ordered from online stores. CCP components typically miniaturized, so working with them should carefully under good lighting of the workplace. A variety of tweezers and a screwdriver is needed to work with small components. Brazing is best to use soldering station with replaceable nozzles, because after the application of the "grandfather of the soldering iron for buckets" to a test CCP doctor may no longer be needed.
The design of the Pocket PC as a whole is simple. The housing is generally composed of a front panel and a back cover (in many models have a battery compartment lid). Often modern PDAs have a single board design, but there are exceptions. Usually for extra boards placed synchronization connectors, power and controls, often handed down to them and radios (Wi-Fi, GSM). Display - this is the most vulnerable and valuable PDA unit. It consists of a matrix with a backlight device and a touch screen. While older iPAQ these two unit have been available separately in the new - a display unit assembled at the factory and its partial repair is difficult, therefore, if the screen is broken, it will require the necessary "donor organs". Battery almost all modern models of lithium-ion or lithium-polymer. He goes down quite rare, but is subject to aging. In some (usually older) models, the battery is located within the housing, and to replace it will have to work with a screwdriver and a soldering iron. Furthermore, there is a model in which is provided a backup battery (used to recharge the RAM during discharge or replacing the primary). Sometimes it is removable (lithium "tablet"), sometimes soldered to the board. Next - the little things, such as a camera, extra fees, pen holder, plugs, caps, buttons, etc .;. repair usually does not cause difficulties (although there are exceptions).
In most cases, the PDA can be repaired at nodes replacement. In fact, the gathering of the two it is easy one PDA (if, say, the first damaged the motherboard, and the second split screen). It does not need a complicated soldering equipment and tools - just a pair of tweezers, and screwdrivers. In addition, the repair is very convenient to have a "guinea" unit, all the nodes which obviously are serviceable - it allows you to determine, for example, the cause of the bands on the display if the screen or motherboard itself to blame.
Moisture and corrosion
The most common reason for breakages - the ingress of moisture apparatus. This can happen very easily (for example, is enough to put in a bag with a wet umbrella CCP), but the "cure" such a machine is sometimes impossible. As a rule, the owner hit the water the CCP puts it a few hours in a warm place, and then tries to include. But by the time the machine is turned irreversibly damaged. Even if the display is extinguished, many inside the CPC circuit are permanently energized and the battery supplies them generously energy required for operation and for galvanic corrosion. Conductor thickness of a few hundredths of a millimeter you need quite a bit of time to cease to exist in the presence of water and a voltage of a few volts. In the multilayer board to find and fix such damage is impossible, and if poured another and display - the CCP can be put on souvenirs: it turned into a useless piece of metal and plastic.
What to do if the CCP is exposed to water or he fell into the water? First of all, you should immediately remove the battery, if it is removable. In this case, data will be lost (though it happens anyway). If we act decisively and quickly, it will be at least a small chance to save the machine. Then it is best to take it to a specialist, who has an ultrasonic bath for cleaning electronics. Attempts to dry on their own PDA, especially without investigating body, usually in vain - the moisture from the body and evaporates bad after battery installation will continue its destructive work.
If a specialist near there, will have to act yourself. Carefully disassemble the machine and wash fee ... water. Just do not tap and distilled, it can be found in a drugstore or auto shop. This will help remove dirt from the board, especially if the PDA has been filled with sweet tea, Coca-Cola or Fanta (they contain phosphoric and carbonic acid). Washing away dirt, residual moisture must be removed, then it is best suited pure alcohol. The board is rinsed in alcohol (total immersion) and dried. For drying it is necessary to warm up the board, can be an ordinary hair dryer. If she will lie down on the table an extra hour for drying - will not harm too. Then, inspection, and if that is not washed off or left plaque, manually using a needle and a tampon, the surface being cleaned.
It is worth making sure that water does not fall into the display unit. The water between the film and the glass of the touch screen at best leads to the formation of a вЂњblind spotвЂќ (pressing in which is not perceived), at worst - to the display's failure. And it is not always noticeable, even the seemingly clean display of the affected PDA is worth some time to dry. In some cases, moisture also causes damage to the display connector (this can be seen on the fly on the contacts, it is not always possible to solve the problem).
After inspecting all the wetted parts of the PDA, including the body cavity, and making sure that there are no drops and no traces of moisture (the body, by the way, you can simply wash it under the tap), proceed to the assembly. If, as a result of resuscitation, the CCP has earned, well, but the likelihood remains that its вЂњlifeвЂќ will not be long. If so, it is unlikely to be repaired even under professional service conditions.
A very large class of failures constitute mechanical defects. Today, manufacturers have generally worked body design, but in some models there are bad individual nodes, which are associated with very characteristic lesions. First of all, this applies to all kinds of caps and latches. For example, if the battery cover is made separately from the battery and is a thin plastic plate with protrusions for locking, they can easily break. As a result, the cover does not fix the battery, and in some cases no longer be included PDA (if provided for in the design of switch that closes when the cover in place, and in some communicators such sensor may be provided and the socket cover SIM-card).
A case in unsuccessful development - model HP iPAQ h2210. Some body parts wear out in a few months. The first is the notorious "bokovinki" - rubber and plastic inserts on the sides, very comfortable, but impermanent. Even with careful operation tire quickly peels off, and the CPC becomes quite pathetic. These parts are inexpensive, but finding them is not easy. Less common defect - decorative bush near the joystick controls. She is fragile, and the appearance of cracks in it leads to the fact that the button is pressed in some areas no longer perceived. As practice shows, any attempt to repair the buttons do not give much effect. Replace button also is not difficult, but only if you manage to find the appropriate item. In the same model, the battery cover is quickly broken when careless handling, as well as in the design of the cover has a closure sensor, the ... See above..
However, most of the damage is due to mechanical stress. If possible, it is best to seal this defect, at least to increase the strength of the case and protect the internal components. If there is no suitable glue or epoxy resin, you can use adhesive tape as a temporary measure.
We disassemble the body
In most cases it is necessary to open the case to repair the PDA. The housing parts are usually joined by plastic retainers and screws. For screws require a screwdriver of the appropriate size, and clips is convenient to share a thin dental instrument (if not, you can try to use an old plastic card edge is cut at an angle). A set of three screwdrivers Torx T-5, T-6 (small six-pointed star) and Philips-0 (small Phillips) is sufficient to loosen the screws of most popular models. With the opening of the housing should be careful not to use excessive force, otherwise have a chance to damage not only the body parts, but also the internal components of the CPC. I never met the model, requiring some specific tools for disassembly of the housing. If body parts can not be separated, it is likely to blame one or more screws, which are hidden under the warranty sticker. It will have to clean off (or puncture) to get access to the screws. In the process of disassembly steps should shoot digital camera - it can simplify subsequent assembly. The main body may also be fixed some electronic components (microphone compartment backup battery chamber), they must be carefully disconnected from corresponding connectors, paying attention to the integrity of the connection cables.
Despite the availability of wireless connectivity, modern PDAs can not do without connectors for different devices: first the external power source to charge the battery. With the development of technology connector dimensions are reduced and, as a consequence, they become less resistant to mechanical stress. Keep in mind that if something can not be inserted into the socket, then you are either doing something wrong or this is not the connector easily. Physical effort is likely to lead to damage and needs to be replaced.
So, the main connectors of the PDA: headphones / headset (the last one for communicators), power / sync (often combined in one), expansion card slots (Secure Digital, Compact Flash, occasionally a Memory Stick), battery connector (hidden inside the case and usually not available without disassembling), connectors for connecting specific expansion devices (almost never found in modern models).
Music lovers who use PDAs as a MP3-player, sometimes notice that when you remove the headphones jack sound basically CCP dynamics does not appear. Sometimes problems arise with the sound when headphones are connected, the connector has to "quiver" to get the sound. This defect is caused by a failed connector design: some types of connectors are not sufficiently elastic contacts. The first problem stems from the fact that the sound on the speaker passes through the headphone jack. When inserting the plug into the socket, he presses on the contact plate, which breaks the contact, and the speaker system is switched off. If after removing the plug contact plate does not return to a place in the system dynamics no sound. This defect can be removed, disassembled and tucked the PDA corresponding connector contact (although in some batches of the contact material is resilient enough and soon the defect manifests itself again, in this case, help is only a replacement connector).
The loss of sound in the headphones can be due to a defect in the socket itself (crack, pollution, poor contact), and poor-quality soldering of the connector on the board: contacts due to the destruction of soldering depart from the contact pads of the board. This defect is easily eliminated by careful soldering of the connector contacts on the board. If necessary, the connector body can be additionally secured with a couple of drops of glue, but carefully so that the glue does not get on the contacts.
Power / Communication
In early models CPC connectors for connecting an external power source / battery charging and synchronization with a PC connector were provided separately, in most modern PDAs are combined into one. Standard for this type of connector is practically non-existent, from model to model in different sizes, pitch and number of contacts. Even if physically identical connectors - pinout them can vary (e.g., HP iPAQ Communicators Qtek), as a consequence - connection "foreign" or power supply cables may cause damage to the PDA. However, the situation is changing in recent years more and more manufacturers use single-row 22-pin connector with contact pitch of 0.5 mm and a fixation part of the foot connector. The trend pleases, but the connector is not distinguished by high mechanical strength. When inserting a mating connector "upside down" or misalignment connector easily breaks down and needs to be replaced, repair it virtually useless.
Sometimes there is another defect: the PDA starts charging or synchronizes only when the connector is pressed in a certain direction (or at a certain position in the dock). As a rule, if the connector is visually intact, this is due to poor soldering and is eliminated by soldering the connector terminals on the PDA card. Sometimes the soldering defect is visually almost invisible and is determined only by shaking the connector contact with a needle.
memory card slot is also used frequently. Does not always remove the card after it is plugged, resulting in the connector may get foreign objects, which would interfere with insert card into place. If the card was able to set in place, but the CCP it "does not see" may be damaged connector (if able to prevent damage to the media itself to check its efficiency by inserting the device to another). In the presence of bright desk lamp or lantern can be, without opening the PDA through the connector slot and make contact to consider the presence or the absence of damage. SD card slot has its own specificity: it provides internal contact group, which is closed when a card is inserted completely. In particular, the already mentioned model HP iPAQ h2210 has a very poor design: in the contact group its connector stuffed dust.
This defect is determined by the dial of the contact group with an ohmmeter when inserting a card.
A variation of the same defect - the card is read, but writing attempts fail. The fact is that on the SD card there is a small plastic "engine" protection record. Its only function is to click on the corresponding sensor in the connector.
Compact Flash connectors have no moving mechanical parts, but their thin pin contacts bend quite easily, and the large dimensions of the socket make it easier for foreign objects to get into it. Therefore, when installing a CF card in the empty connector, you need to make sure that nothing has fallen there, and gently blow the connector.
The battery within the CCP requires periodic charging from an external source. Usually it comes bundled with a standard power supply, which provides charging from the mains. Additionally available adapter for charging from the cigarette lighter socket of the car, solar panels and other devices. In any case, these devices must provide appropriate voltage settings on the output connector, a voltage deviation may cause damage, even catastrophic, PDA. For this reason, you should not use cheap "Chinese" power supplies, and especially "with an adjustable output voltage" - a chance to bring PDAs into disrepair very large. In older models, the CCP did not perform too well supply chain security elements their function, and the chances for its repair were small; often encountered situation of electric breakdown of the main components (up to a processor). The new models this problem is generally solved by now to recover enough to replace the protective elements. a protection circuit is generally composed of the current fuse and nonlinear semiconductor whose resistance drops abruptly when a voltage is exceeded (so-called protective diode). The fuses are in the form of chips, their serviceability easily established with an ohmmeter: the inner conductor is damaged fuses and interrupts the circuit.
The protective diodes, as a rule, are made in the form of glass cylinders and, if damaged, punch through, that is, they short circuit the circuit.
There may be several fuses and protective diodes on the board. However, in some cases other elements are damaged, which can be established visually, paying attention to blisters on the details and traces of soot. Conductors on the board may burn out. In many cases, replacing defective elements and duplicating the burned conductors with a wire, you can restore the efficiency of the PDA.
Nevertheless, it is better not to use cheap power supplies and cigarette lighter adapters, and also not to try to adapt the adapters from cell phones - they give much less current. In this case, it is much easier to prevent a problem than to eliminate its consequences.
In most cases, the CCP applies lithium ion or lithium polymer batteries, as having the greatest capacitance in relation to volume. Their advantage: there is no effect of "memory"; drawbacks - a significant reduction in performance at low temperatures, a limited service life (up to 500 charge-discharge cycles) and operation (about three years) before significant capacitance drop. The new models PDA battery is usually removable - so the user can easily replace it or use several batteries for longer battery life. In older models PDA battery is built into the body, its replacement requires disassembly of the CPC and the work of a soldering iron. 4,1-4,2V charged battery has a voltage discharged - about 3V. Discharge 3B below leads to degradation - reducing battery capacity and a long stay in a discharged state - to the damage of the battery. If you want to store the lithium battery, it is recommended to charge it completely before storing.
The batteries consist of the actual вЂњlithium canвЂќ and a rather complex electronic вЂњstuffingвЂќ, which is necessary for solving three problems:
protection of the battery against overcharging and short circuit;
"Accounting" the amount of energy in the element and its consumption, which allows you to give accurate information about the percentage of charge and predict the time of the PDA;
control mode charge-discharge battery cell.
a large number of replacement batteries is available for modern models of PDAs, including inexpensive enough unoriginal. The question of the actual battery repair for old PDA models with built-in battery or models, batteries which are no longer available. Battery Failure is manifested as a reduction in battery life. To clarify the problem, to get directly to the contacts of the lithium cell, and measure the voltage, preferably after a full charge. If the voltage is less than 2.5V, the element unfit for further use; he either already degraded completely, or on the verge. If the voltage from 3 to 4.2V, it can be loaded with sample. As it is known, one of the important characteristics - the internal resistance of the power supply. you can imagine the real source of power as the ideal, and it is included in series with a resistor that limits the power output of the useless turns electricity into heat. In practice the cell voltage measured at no load, then it connects to a load resistor and the voltage is measured again. It is then calculated by the formula internal source impedance. For example, let the battery voltage is 4.0, the resistance of the load resistor of 10 ohms, and when you connect a resistor voltage drops to 3.9. (4-3,9) / (3.9 / 10) = 0.1 / 0.39 = 0.26 ohms. This value is acceptable, but close to the upper limit. If the internal resistance of the cell is greater than 0.3 ohms, the lithium should be changed.
It is interesting that for many older models iPAQ PDAs and other fine lithium batteries from the model aircraft. The main criterion - the geometrical dimensions, particularly the thickness should not exceed the limits in place in the housing (about 4 mm). Excellent choice of batteries can be found in the American online stores for model airplanes. The new element is soldered to the corresponding terminals "+" and "-" on board battery controller (or flexible riser card in models 31, 36 and 37 minutes series). Polarity confused highly undesirable - the controller can be irreversibly damaged. The wires must be carefully insulated and secure in order to avoid a short circuit, the fireworks in your pocket is very undesirable. Brazing aluminum require a special solder and flux. Some online stores sell ready-made battery controllers for specific models of PDAs, but the price of such nodes can greatly exceed the price of the usual elements, and not all models are available. However, in this case the replacement is greatly simplified and can be afford to the owner of the PDA.
The display unit is the most important (and, as a rule, the most expensive) part of the PDA. In many cases, repairing a PDA with a damaged display may be impractical (very expensive), so you should handle the PDA carefully and protect it from impacts.
The display consists of several elements sometimes different manufacturers, but the general principles are generally the same. The main element - matrix LCD, then - the backlight assembly. In the early models of the display illuminate a thin electroluminescent film is usually green, but it is suited only for monochrome screens. The next step was color displays, which required a bright white light. It was performed by using a thin fluorescent lamp and a light guide located above the matrix (so-called reflective display). Lamps were expensive, they have a limited life and very greedy, and a high voltage inverter nodes still not very reliable. The next step was LED backlight and transflective (transflective) display, wherein the illumination light guide was again placed under the display matrix. The result is a good quality and brightness of images with low power consumption.
Damage to the LCD matrix is вЂ‹вЂ‹easy to identify visually, it usually looks like a dark spot on the display and is visible even when the PDA is turned off.
If the LCD matrix is вЂ‹вЂ‹damaged, the only way to repair it is to replace it with a similar one. Unfortunately, reducing the size of the display and the thickness of the glass plates led to a decrease in the strength of the display. In addition, in modern models, the cable (cable) of the display is usually glued to the matrix, so even if the integrity of the matrix is вЂ‹вЂ‹preserved, damage to or breakage of the cable also leads to the need to replace the entire assembly.
Another important part of the display - touch screen. It consists of a flexible film and a glass substrate. Despite the apparent simplicity, the design is quite complex. On a film vertical conductors deposited on the glass - the horizontal; In addition, the glass deposited small dots of transparent plastic to prevent closure of the conductors on the glass and the film in the "idle" state. Pressing the stylus on the screen results in deflection of the film and the closure of the conductors on the glass and the film. Since the resistance of the transparent conductor is relatively large (hundreds of ohms), the auxiliary controller can determine the point of pressing the screen (but only if the pressing takes place in one location). Obviously, the damage of the film or glass leads to rupture all or part of the conductors and the disappearance of the sensitivity of some or all of the touch screen surface (in rare cases it is retained, but the accuracy of determining the touch locations speak not have to). Contact with liquids also negatively affect the operation of the touch screen display even after the drying operation can be irreversibly broken.
While older matrix backlight unit and the touch screen is delivered separately, thereby enabling to reduce the cost of repair PDA. The new models are officially considered that the display unit is factory-wired and is one - however, as a rule, it is possible to divide the display elements and the touch screen. If you can find a PDA that has damaged other display element, you can try using a serviceable part for repair. The conductors of the touch screen can be withdrawn using a separate cable or soldered on a common base display cable. In the latter case it is necessary to replace the cable carefully unsolder the faulty touch screen and solder the cable correctly.
As a rule, the display assembly has a metal case bonded to each other by protrusions on its parts, so it is possible to gently squeeze the projections with tweezers to separate the halves of the case, that is, to get a separate touch screen and a matrix, and then put together healthy halves.
During this repair, it is very important not to allow dust particles to get inside the display assembly - they will be perfectly visible when the backlight is on. For purging the assembly from dust it is recommended to use a can of compressed dried gas: it is usually used for purging office equipment from dust and is sold in many consumables stores.
The iPAQ rz1710, hx2110, rx3715 models have interchangeable displays, like the PDA iPAQ h1930, h1940, h4150, h4350, h6340 (but only within the listed model range).
When you work with the display it is recommended to use plastic or thin latex gloves so as not to be left in unnecessary places fingerprints. Attention is drawn to the fact that different models of displays produced by different manufacturers may be incompatible, despite the same connector. In this case, you should carefully examine the data and numbers on a label on the back side of the display. Improper display can be quite serviceable damage the motherboard, and the CCP completely different manufacturers may well use the same display model.
We reviewed the main methods for repairing defects and handheld computers, but do not touch the issue of upgrading and replacement of system software "pickpockets"; this is a separate big topic. In conclusion, I would like to point out a few little things that might be useful. Owners of PDAs family of HP iPAQ h1930 and h1940 (they are still widely used) should be kept in mind that these devices have a problem with the overflow of a user-accessible area of вЂ‹вЂ‹the internal flash memory (iPAQ FileStore). In this case there is risk of damage to the contents of the system areas of the flash memory and the output of the CPC system. If the unit is under warranty, you can safely apply to the service center - if not, try to restore the system, copied to a memory card "image" from the error PDA same model (with the successful outcome of the experiment - nothing ever write in the FileStore). A similar problem was also observed in the HP iPAQ hx4700 model, but not so often, the prevalence of this defect is apparently connected with the peculiarities of some of the versions of the firmware. The user model HP iPAQ h2210 be aware that stick "side cover" practically useless, it is better to change them. Four-way controller and not repairable. Owners of almost all modern PDAs will be useful to know that the CCP can be charged by USB, dopayat appropriate jumper in sync cable. CPC is useful for all stick protective film, the scratches on the touch screen zapolirovat almost impossible.
And most importantly - I wish that the information and recommendations from this article were never useful to you ...