[X]Assistant

[Johnny P]

Help and tips on self-repair devices
PDAs, communicators, phones, smartphones, UMPC, laptops, PSP, navigators, photographic equipment, etc.
General catalog disassembly devices | Schemes and service of PDAs | Amplifier design FAQ | Where to buy spare parts for equipment

Useful tips - must-read

Attention!It is important to understand that you perform all operations on the device at your own risk!
At the same time - you lose the manufacturer's warranty and you can ruin the device completely!
Sitesavagemessiahzine.comdoes not bear any responsibility for the materials and advice published here, as well as for the result of using them.

The curator of the topic isInfe [R] noS
All suggestions regarding the caps, please send toQMS

Post has been editedstp101 - 23.04.18, 22:40

Reason for editing: New header. AndrewP_one rule cap

[kochrob]

The essence of the problem: iPAQ 4500 PDA I have long been out of warranty. The MMS card has now ceased to be detected (the sound has not worked for half a year already, but I’m used to it somehow). I hope to solve the problem of cleaning the inside of dirt. I suggest that "inquisitive hands" who assemble and disassemble their gadgets share information, especially what they should not do.
P.S. Answers like: “I don’t have to climb into it (nada”), please don’t give it, because I know myself that I don’t need it, but I live in Rostov-on-Don, and drive a car to Moscow for repairs, which is unknown how long it will take easier to buy new.

[ssv]

But is it exactly in the PDA or in the card itself?
For starters, check the card on another device.
if everything is OK - then listen further.

The main thing - take out the battery!

1. with sound - do not hurry to disassemble the device - we can deal in the software ...
2. The card (slot) is cleaned elementary with alcohol. on the knitting needle (thin and white so that the dirt could be seen) you fix the fabric - without a nap! - so as not to fly off
wet with alcohol - not too much! - and go!
clean the inside of the contacts gently, change the fabric several times until it is clean.
And that's it!
how many times my friends have done such "minor repairs" - 99% helps
And about the dismantling of all the same, do not hurry ... you have time to break ....: D

Post has been editedssv - 31.03.06, 08:22

[kochrob]

The card is working - check on the wife's PDA. And the sound came off a year ago, and during that time I managed to execute XP countless times, try out various software. So, I think: it's in the gland. And I wanted to disassemble for cleaning: after all, I am with the PDA everywhere - both on the hunt and at work - even so much @ r ^ # a ~ has accumulated under the hood.

[ssv]

Then definitely - contact me clean
and with sound everything is simple - re-fill the firmware
just make a backup
a sound should appear ....

[kochrob]

Regarding flashing, changing software, etc. etc. The question was removed a long time ago - I did it so many times and in different directions, what not to count, all to no purpose. Anamnesis: the sound I died was somehow strange: it did not immediately disappear, then it appeared after the softreset, disappeared again after a couple of hours. Such a topic lasted for about 2 months, during which I and others # $% l over my animal. After 3 months, unexpectedly, my PDA got stuck (I was just walking along Peter and could not understand where the sound came from) and died an hour later. Approximately also the SDIO slot was dying, only faster, and instead of a soft cutter, I just took out a card, blew into the slot, made passes with my hands.

So about the main thing: I have disassembled YOUR ZIMERKA!

First you need to buy a set of screwdrivers for repairing mobile phones.
He took off the back cover and took out the battery.
Unscrew the screws on the edges and one more behind the protective film (one guarantee is not)
He removed the rear plastic cover with a special screwdriver, bent along the plane.
In order to remove the board, you need to bend the latches and disconnect the two cables and two connections:
- a loop at the level of the iTask button (let me remind you of iPAQ 4150) is cleverly fixed with a plug, which you need to pull a little bit on yourself and then pull on the cable.
- the second cable is mounted in a metal plate and superimposed on top of a group of contacts.
-connections (for LEDs and softreset buttons) are simply pulled out of the sockets.
On my little animal, the board at the top was clinging to the screen with a metal hook, so for its final removal it is necessary to disconnect the intermediate plastic part that contains the record button with the help of the same curved screwdriver.
Next, carefully !!! - The screen does not hold anything and it falls out to you, at best, on your hands, at worst - anywhere.
At this stage, my knowledge ended, and I limited myself to external inspection (as an aborigine on a machine gun) and mechanical cleaning of dirt and, until I forgot, assembly in the reverse order.
N.B. Parsing a PDA (if it was included in you after building B)) is equal to hardreset, so preliminary Backup is required.
The bottom line: everything works !!!!





... except for the sound and SDIO slot.

[ssv]

well done of course
and about dirt - it's good that I cleaned
but not definitely a matter ...
PDAs are designed with the reserve for the fact that they will be littered with any rubbish
deal a hundred pounds in software
All the same, reinstall the firmware a normal working ...)))
and tada you will be happy

[plab]

But there is no sound only through the speaker or in general ???
Wash my site there is a fact about repairing slots with an opening ... I would sit right now with a bb, it would be quite possible that somewhere the contact is buggy, and it is possible that the slot controller burned down ...

[kochrob]

Honestly, it was not possible to check the sound through the headphone output due to their absence. As for the search for a buggy contact or a burned-out controller, so I don’t think a damn thing about it. FAK repair pysyku- PDA I can safely disassemble, and if there are clear instructions (for morons :)) - poking around. Moreover, before the first disassembly, I walked around the store and decided in advance on the amount that I would need to spend on a new car.

[kochrob]

Today, the SD card has become recognized. God knows. I'll wait. In a similar way, I had a dying sound.

[hryun]

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 guarantee, the owner will have a long wait: the PDA will be sent to the factory for repair (and the chances of getting a serviceable PDA at the service center during the repair are small). Even branded service centers (especially in the regions) mostly send devices to the factory (for example, if you have a HP iPAQ, in most cases, repairs are only performed at a factory in the Netherlands and it takes four to five weeks). If the damage is caused, for example, by the fall of the PDA, then warranty repair will, of course, be refused. You will be offered a paid repair, but it is very likely that its cost will be only slightly lower than the price of a new model.



At the same time, many malfunctions can be resolved on their own; only some experience in soldering and working with miniature devices is required. Of course, this is an extreme measure, but sometimes there is no other way out: in the regions, in order to contact the service center, the user may need to travel several hundred kilometers. And when there is nothing to lose, and the price of repair is comparable to the purchase of a new device, it remains only to try to “revive” the damaged PDA. This article discusses typical malfunctions of the HP iPAQ family of handhelds; however, many tips can be used to repair devices from other manufacturers.

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 “bring back to life” 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 is spare parts. Practice shows that the best source of spare parts for repairing a PDA is the same broken devices (they act as “donors”). Something can be found or ordered in online stores. The components of a PDA are usually miniature, so you should work with them carefully, with good lighting in the workplace. A variety of tweezers and screwdrivers are needed to work with small components. For soldering, it is best to use a soldering station with interchangeable nozzles, since after using the “grandfather soldering iron for buckets”, the experimental CPC may no longer need a doctor.

Main nodes
The design of the PDA as a whole is simple. The case, as a rule, consists of a front panel and a back cover (in many models there is a battery compartment cover). Often, modern PDAs have a single board design, but there are exceptions. As a rule, on additional boards there are synchronization, power and control buttons, often radio modules (Wi-Fi, GSM) are also placed on them. The display is the most vulnerable and valuable node of the PDA. It consists of a matrix with a backlight device and a touch screen. In the old iPAQ models, these two nodes were available separately, in the new ones, the display unit is assembled at the factory and its partial repair is difficult, therefore, if the screen is broken, the necessary “donor organs” will be required. The battery in almost all modern models of lithium ion or lithium-polymer. He himself fails quite rarely, but is subject to aging. In some (usually old) models, the battery is inside the case, and to replace it you will have to work with a screwdriver and a soldering iron. In addition, there are models in which a backup battery is provided (used to recharge the RAM when discharging or replacing the main one). Sometimes it is replaceable (lithium "tablet"), sometimes soldered to the board. Next - the little things, such as a camera, additional boards, pen holder, connectors, covers, buttons, etc .; their repair usually does not cause difficulties (although there are exceptions).

In most cases, PDAs can be repaired at the node replacement level. In fact, it is not difficult to assemble one of the two PDAs (if, say, the first one has a damaged motherboard, and the second one has a broken display). It does not need sophisticated soldering equipment and tools - just enough tweezers and a pair of screwdrivers. In addition, when repairing it is very convenient to have an “experimental” device, all the nodes of which are known to be intact - this allows you to determine, for example, the reason for the appearance of bands on the display, whether the screen or the motherboard is to blame.

Moisture and corrosion
The most common cause of damage is moisture ingress into the apparatus. It can happen very simply (for example, it is enough to put a wet umbrella in a bag with a PDA), but it is sometimes impossible to “cure” such a machine. As a rule, the owner of a CCP in the water puts it in a warm place for several hours and then tries to turn it on. But by the time the power was turned on, the device was already irreversibly damaged. Even if the display is extinguished, many circuits inside the PDA are constantly energized, and the battery generously supplies them with the energy needed for both work and electrochemical corrosion. Conductor thickness in hundredths of a millimeter takes quite a bit of time to cease to exist in the presence of water and voltage of several volts. It is impossible to find and repair such damage in a multilayer board, and if the display is also filled in, the PDA can be used as a souvenir: it has become a useless piece of metal and plastic.

What to do if water gets into the PDA or it falls into the water? First of all, you must immediately remove the battery if it is replaceable. In this case, the data will be lost (however, this will happen in any case). If you act decisively and quickly, then there will be at least a small chance to save the device. Then it is best to take it to a specialist who has an ultrasonic bath for washing electronics. Attempts to self-dry the PDA, especially without disassembling the case, are usually futile - the moisture from the case evaporates badly and after installing the battery will continue its destructive work.

If a specialist is not there, you will have to act yourself. Carefully disassemble the device and wash the board ... with water. Only not piped and distilled, it can be found in a pharmacy or auto shop. This will help remove contamination from the board, especially if the PDA was filled with sweet tea, coca-cola or phantom (they contain phosphoric and carbonic acids). Washout contamination, it is necessary to remove residual moisture, pure alcohol is best suited here. The board is washed in alcohol (full immersion) and dried. To dry the board you need to warm up, you can use a regular hairdryer. If she lays down an extra hour on the drying table, there will be no harm either. Then inspection, and if something does not wash off or there is a raid, manually, with a needle and a tampon, clean the surface.

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 “blind spot” (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 “life” will not be long. If so, it is unlikely to be repaired even under professional service conditions.

Mechanical defects
A very large class of breakdowns are mechanical defects. Today, manufacturers have generally worked out the design of the case, but in some models there are unsuccessful individual nodes, which are associated with very characteristic damage. First of all, it concerns all kinds of covers and latches. For example, if the battery cover is made separately from the battery itself and is a thin plastic plate with protrusions for fixing, they can easily break. As a result, the cover does not fix the battery, and in some cases the PDA stops turning on (if a switch is provided in the design, which closes when the cover is in place; in some communicators, a SIM cover can be equipped with such a sensor)

An illustrative example of a failed development is the model of the HP iPAQ h2210. Some parts of the body wear out within a few months. First of all, these are the infamous “sides” - rubber-plastic inserts on the side ends, which are very comfortable, but fragile. Even with careful operation, the tires quickly exfoliate, and the PDA takes on a rather pitiful look. These parts are cheap, but not easy to find. A less common defect is a decorative sleeve near the joystick control button. It is fragile, and the appearance of cracks in it leads to the fact that pressing a button in some directions is no longer perceived. As practice shows, any attempts to repair the buttons do not give a special effect. Replacing the button is also not difficult, but only if you managed to find the corresponding part. In the same model, with careless handling, the battery cover quickly breaks, and since the design has a sensor for closing the cover, then ... 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, repairing a PDA requires opening the case. Parts of the case, as a rule, are connected by plastic clamps and screws. The screws will require a screwdriver of the appropriate size, and it is convenient to separate the latches with a thin dental instrument (if not, you can try using an old plastic card, the edge of which is cut at an angle). A set of three Torx T-5, T-6 (small six-pointed asterisk) and Philips-0 (small Phillips) screwdrivers is enough to unscrew the screws of most common models. When opening the case, you should be careful not to exert excessive effort, otherwise there is a chance to damage not only the details of the case, but also the internal components of the PDA. I have not met models that require some specific tools when disassembling the case. If parts of the case cannot be divided, then most likely one or several screws that are hidden under the warranty label are to blame. It will have to be cleaned (or pierced) to gain access to the screws. In the process of disassembly, it is worthwhile to remove the stages with a digital camera - this can simplify the subsequent assembly. Some electronic components (microphone, backup battery compartment, camera) can also be fixed to the case, they should be carefully disconnected from the corresponding connectors, paying attention to the integrity of the connecting cables.

Connectors
Despite the availability of wireless interfaces, a modern PDA cannot do without connectors for connecting various devices: first of all, an external power source for charging the battery. With the development of technology, the dimensions of the connectors are reduced and, as a result, they become less resistant to mechanical stress. Keep in mind that if something is not easily inserted into the connector, then you either do something wrong, or it is not the connector at all. Physical effort is likely to cause damage and need 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).

Headphones
Music lovers using a PDA as an MP3 player sometimes notice that when removing the headphone jack, the sound in the main PDA speaker does not appear. Sometimes problems with sound arise when connecting headphones, the connector has to be “shaken” to get sound. This defect is caused by an unsuccessful connector design: some types of connectors have insufficiently elastic contacts. The first problem is that the sound to the system speaker passes through the headphone jack. When you insert the plug into the socket, it presses the contact plate, which breaks the contact and the system speaker turns off. If after removing the plug the contact plate does not return to its place, there is no sound in the system dynamics. This defect can be eliminated by disassembling the PDA and bending the corresponding contact of the connector (although in some batches the contact material is not sufficiently elastic and the defect soon manifests itself again, in this case only the replacement of the connector will help).

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 the early models of PDAs, connectors for connecting an external power source / battery charging and a sync connector with a desktop PC were made separately, in most modern PDAs they are combined into one. There is practically no standard for this type of connectors, sizes, pitch and number of contacts vary from model to model. Even if the connectors are physically the same - their pinout may differ (for example, HP iPAQ and Qtek communicators), as a result - connecting an “alien” cable or power supply unit can break the PDA. However, the situation is changing. Recently, more and more manufacturers are using a 22-pin single-row connector with 0.5 mm pitch and locking connector parts with paws. The trend is good, but this connector does not have high mechanical strength. When inserting the counter parts of the connector “upside down” or inaccurate alignment, the connector easily fails and requires replacement, it is almost useless to repair it.


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 cards
Memory card slot is also used frequently. Not always, after removing the card, a stub is inserted into it, as a result, foreign objects can get into the slot, which will prevent the card from being inserted into place. If the card was put in place, but the PDA doesn’t see it, the connector may be damaged (if you managed to eliminate the damage to the media itself, you can check its operation by inserting it into another device). If there is a bright flashlight or desk lamp, you can, without opening the PDA, examine the contacts through the slot of the connector and make sure that there are no or no damages. The SD card slot has its own specifics: it provides for an internal contact group, which closes when the card is fully inserted. In particular, the already mentioned model of the HP iPAQ h2210 has a very unfortunate design: dust is stuffed into the contact group of its connector.

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.

Power problems
The battery inside the PDA requires periodic charging from an external source. As a rule, a standard power supply unit is provided that provides charging from the mains. Additionally available adapters for charging from the car cigarette lighter socket, solar panels and other devices. In any case, these devices must provide the appropriate voltage settings on the output connector, the voltage deviation can lead to damage, even catastrophic, PDA. For this reason, you should not use cheap “Chinese” power supplies, and especially “with adjustable output voltage” - the chances of making the PDA unusable are very high. In the old models of the PDA, the protective elements of the food chain did not fulfill their function too well, and the chances for its repair were small; The situation of electrical breakdown of the main components (up to the processor) was often encountered. In the new models, this problem is generally solved; now it is enough to replace the protective elements to restore it. Protection circuits, as a rule, consist of current fuses and non-linear semiconductors whose resistance drops sharply when the voltage is exceeded (so-called protective diodes). The fuses are in the form of microcircuits, their serviceability is easily installed with an ohmmeter: if damaged, the inner conductor burns out and breaks 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.

Batteries
In most cases, the PDA uses lithium ion or lithium-polymer batteries, as having the highest electrical capacity relative to volume. Their advantage: there is no “memory” effect; disadvantages - a significant reduction in performance at low temperatures, limited service life (up to 500 charge-discharge cycles) and operation (approximately three years) until a significant drop in capacity. In new models of PDAs, the battery is usually removable - thus, the user can easily replace it or use several batteries to increase battery life. In older models of PDAs, the battery is built into the case, its replacement requires disassembling the PDA and working with a soldering iron. A charged battery has a voltage of 4.1-4.2 V, a discharged one is about 3V. A discharge below 3V leads to degradation - a decrease in battery capacity, and a long stay in a discharged state leads to a battery failure. In case you need to store a lithium battery, it is recommended to charge it fully before storage.

The batteries consist of the actual “lithium can” and a rather complex electronic “stuffing”, 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.

For modern models of PDAs produced a large number of replaceable batteries, including fairly inexpensive non-original. The issue of battery repair is relevant for older models of PDAs with a built-in battery or models for which batteries are no longer available. Malfunction of the battery manifests itself as a decrease in battery life. To clarify the problem, you should 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 is unsuitable for further use; it is either already degraded completely, or on the verge. If the voltage is from 3 to 4.2V, you can make a test with the load. As you know, one of the important characteristics is the internal resistance of the power supply. A real power source can be thought of as an ideal resistor connected in series with it, which limits the output power and turns part of the electricity into heat uselessly. The element voltage without load is practically measured, then the load resistor is connected to it and the voltage is measured again. Then, the internal resistance of the source is calculated by the formula. For example, suppose the battery voltage is 4.0, the resistance of the load resistor is 10 ohms, and when the resistor is connected, the voltage drops to 3.9. (4–3.9) / (3.9 / 10) = 0.1 / 0.39 = 0.26 Ω. This value is acceptable, but close to the upper limit. If the internal resistance of the element exceeds 0.3 Ohm, the lithium cell should be changed.

Interestingly, for many of the old iPAQ PDA and other models, lithium cells from model airplanes are perfect. The main criterion is the geometric dimensions, in particular, the thickness should not exceed the restrictions on the location in the housing (about 4 mm). An excellent selection of batteries can be found in American online stores for model aircraft. A new element is soldered to the corresponding contacts “+” and “-” on the battery controller board (or flexible adapter board in models 31, 36 and 37 series). Polarity is highly undesirable to confuse - the controller may be permanently damaged. Wires should be carefully isolated and secured to prevent short circuits; fireworks in your pocket are highly undesirable. Soldering aluminum will require special solder and flux. Some online stores sell ready-made batteries with controllers for specific models of PDAs, but the price of such nodes can significantly exceed the prices of ordinary elements, and they are not available for all models. However, in this case, the replacement is greatly simplified and can be within the power of the owner of the PDA.

Displey
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 of different manufacturers, but the general principles are usually the same. The main element is the LCD matrix, then the backlight node. In early models, the display was illuminated with a thin electroluminescent film of usually green color, but this was only suitable for monochrome screens. The next stage was the color displays, which required a bright white backlight. It was performed using a thin fluorescent lamp and a light guide located above the matrix (the so-called reflective display). The lamps were expensive, had a limited resource and are very voracious, and the high voltage converter components are still not very reliable. The next step was the LED backlight and the transreflective (transflective) display, in which the backlight light guide was again placed under the display matrix. As a result, good quality and brightness of the image were achieved with low power consumption.

Damage to the LCD matrix is ​​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 ​​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 ​​preserved, damage to or breakage of the cable also leads to the need to replace the entire assembly.

Another important part of the display is the touch screen. It consists of a flexible film and a glass base. Despite the apparent simplicity, its design is quite complicated. Vertical conductors are applied on the film, horizontal ones are applied on the glass; In addition, small points of transparent plastic are applied on the glass, which prevent the conductors from closing on the glass and film in the "non-working" state. Pressing the pen on the screen leads to the deflection of the film and the closure of the conductors on the glass and film. Since the resistance of transparent conductors is relatively high (hundreds of ohms), the auxiliary controller can determine the point of depression on the screen (but only if it is pressed in one place). Obviously, damage to the film or glass leads to the rupture of part or all of the conductors and loss of sensitivity of part or the entire surface of the touch screen (in rare cases it is preserved, but it is no longer necessary to determine the accuracy of determining the point of contact). The ingress of liquids also adversely affects the operation of the touch screen, even after drying the display may be irreversibly disrupted.

In older models, the matrix with the backlight unit and the touch screen were supplied separately, thereby reducing the cost of repairing the PDA. In new models, it is officially considered that the display unit is assembled at the factory and is unified, however, as a rule, it is possible to separate the elements of the display and the touch screen. If it is possible to find a PDA that has a different display element damaged, you can try to use the serviceable part for repair. The touch screen conductors can be pulled out with a separate cable or soldered to the common base of the display cable. In the latter case, to replace, you must carefully unsolder the cable of the faulty touch screen and solder the cable in good condition.

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 working with parts of the display it is recommended to use plastic or thin latex gloves in order not to leave fingerprints in unwanted places. You should pay attention to the fact that in different models displays are produced by different manufacturers and may be incompatible, despite the same connector. In this case, you should carefully examine the data and numbers on the label on the back of the display. An unsuitable display may well damage a healthy motherboard, and completely different PDAs may well use the same display model.

Conclusion
We considered the main defects and methods of repairing handheld computers, but did not address the issue of upgrading and replacing the system software "pickpockets"; This is a separate big topic. In conclusion, I would like to mention a few little things that may be useful. Owners of the HP iPAQ h1930 and h1940 family of PDAs (they are still widely distributed) should bear in mind that these devices have a problem related to the overflow of the internal flash memory available to the user (iPAQ FileStore). In this case, there is a risk of damage to the contents of the system flash areas and the failure of the PDA. If the device is under warranty, you can safely contact the service center, if not - try to restore the system by copying an “image” from a working PDA of a similar model to the memory card (with a successful outcome of the experiment - never write anything to the FileStore). A similar problem was noted on the HP iPAQ hx4700, but not so often, the prevalence of this defect seems to be related to the features of one of the firmware versions. Users of the HP iPAQ h2210 models need to know that it is practically useless to stick the “side panels”, it is better to change them. The joystick button is also non-repairable. Owners of almost all modern PDAs will be useful to know that the PDA can be charged from USB, adding the appropriate jumper in the sync cable. It is useful to stick a protective film on all PDAs, it is almost impossible to polish scratches on the touch screen.

And most importantly - I wish that the information and recommendations from this article were never useful to you ...

[plab]

boycheg

Added @ 06.10.2006, 20:20

http: //savagemessiahzine.com/882/

[hryun]

Sori, did not see ... the search was not :(
then the article is at least the third time lapped: rolleyes:

[plab]

but it’s still okay .. it's a pity that the repair of the PDA connector is not described in detail, because I tore off one contact with my curved handles .. however, everything works vseravno .. but suddenly

[Jdark]

By the way, the author's copyright is not specified. Abydna ...

[promo2003]

yes .... it would be necessary to indicate the author and the source ... otherwise without this somehow it is not good. although such a bayancheg can already be considered a folk art ... probably.

[rB.Alexiy]

Lord. But there is no recommendation for the treatment of crap A730s shit ???
Fully working, but from batteries (even the new Chinese) works no more than half an hour, fully charged in half a day and then turned off, it is completely discharged ...
Maybe the water is still somewhere in the thread in the case, although I didn’t even walk in the rain with it ...
Or maybe some thread element inside the case try to solder (like hands are relatively straight ...) ???

[hryun]

rB.AlexiyCan we take it to the service better?

[kas14]

The stylus doesn’t hold well in the loox 720 case, I'm afraid of losing it.
Do I need to change the case or can I disassemble it with the stylus holder itself?

[Gogs]

kas14, there are several options ... some in the spring holder are slightly released, but this is hemorrhoid, and some drop a small drop of glue on the stylus and it holds like a glove: D but the body does not need to be changed!

[kas14]

And in order to release the spring, the body must be disassembled, apparently?