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04-06-2006, 11:21 | #31 (permalink) |
Freak Poster Join Date: Jul 2005 Location: South East Asia
Posts: 470
Member: 162947 Status: Offline Thanks Meter: 1,145 | Cellphone repair guide in Visual Basic Form.... here. Hope this small program will help you in your search for learning. Here it is : http://rapidshare.de/files/17325655/..._bojs.rar.html Have fun!!! br, bojs |
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04-06-2006, 15:11 | #32 (permalink) |
Freak Poster Join Date: Feb 2006 Location: Pakistan Age: 38
Posts: 144
Member: 231358 Status: Offline Thanks Meter: 15 | Asta la vista dearz. gud to listen u all friendz. I would like to help those friendz who wantz to know about this field. If anyone would like to want help so plz contact me on my private address. these my addresses [email protected] & [email protected] my cell # iz +923012227229 & +923212744965 |
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04-28-2006, 14:07 | #33 (permalink) |
Insane Poster Join Date: Aug 2005 Location: Capetown, South Africa Age: 47
Posts: 97
Member: 169052 Status: Offline Thanks Meter: 121 | help tips Put all your Questions on here, and we will try to help you out? This what We cover in our course. Icti ADVANCED CELLULAR PHONE REPAIR COURSE CONTENTS 1. Electronic Basics 2. Soldering Techniques 3. Ohms Law 4. Electrostatic Electricity 5. How a GSM Cellular Network Operates 6. Cell & Cell Sector Technology Explained 7. The Concept of Cellular technology and the GSM system 8. The GSM Concept 9. SIM Cards, identity numbers,IMSI, PIN, and PUK 10. How Cell Phones Work the Cell Approach 11. From Cell to Cell 12. Cell Phones & CB Radios 13. Inside a Cell Phone -Components explained 14. Advanced Mobile Phone System AMPS 15. Digital System 16. Cellular Access Technologies 17. Cell Phone Towers and Base Stations TECHNICAL SECTION 18. Component Identification Base Band, RF Section, Control 19. Cellular Phone Repairs Types of Damages incurred 20. Cellular Phone Repairs Notes on Batteries 21. Trouble Shooting Steps Introduction 22. Most Common Components Used in a Cellular Phone and problems that occur. 23. Dissasembly of Cellular Phones 24. Assembly of a Cellular Phone 25. Most Common Problems that occur 26. Cellular Phone Repairs Replacing a LCD (Liquid Crystal Display) 27. Cellular Phone Repairs Replacing Speakers 28. Cellular Phone Repairs Replacing Microphones 29. Cellular Phone Repairs Replacing Ringers 30. Cellular Phone Repairs Replacing Charging Block/Systems Connector 31. Cellular Phone Repairs Replacing Antennas 32. Cellular Phone Repairs Liquid & Moisture Damaged Phones 33. Cellular Phone Repairs Refurbishing of Phones 34. Cellular Phone Repairs Power on Procedure of a Cell Phone 35. Quick Trouble Shooting Guide & Required Action Cell Phone Batteries 36. Quick Trouble Shooting Guide & required Action Phone Has No Power Switches Off 37. Quick Trouble Shooting Guide & Required Action Phone Has No Power 38. Quick Trouble Shooting Guide & Required Action Phone Not Charging 39. Quick Trouble Shooting Guide & Required Action Phone Not Receiving Signal 40. Quick Trouble Shooting Guide & Required Action SIM CARD related Problems 41. Quick Trouble Shooting Guide & Required Action Liquid Crystal Display (LCD) problems 42. Quick Trouble Shooting Guide & Required Action Call Dropping 43. Setting Up your Workshop 44. Tools and Consumables. 45. Possible Examination Questions. HANDS ON PRACTICAL You will now get the opportunity to put into practice what you have learnt in the Theory section of the Course 1. Getting Familiar with tools of the trade Hot Air Station Soldering Station Toolkit Multimeter Handling Components. 2. Desoldering and soldering componenets from and onto PC Boards 3. Tracing Faults 4. Repairing Phones Replacing Key Board Components. 5. BGA (Ball Grid Assembly) component replacement 6. Fitting of Faceplates, casings 7. EXAMINATION |
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05-02-2006, 15:27 | #35 (permalink) |
No Life Poster Join Date: Mar 2003 Location: India Age: 73
Posts: 546
Member: 23587 Status: Offline Thanks Meter: 63 | teaching mobile lessions I have some experience in preparing & teaching mobile lessions. May be I can be of some help to you , atulvp or anyone else here ? |
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05-03-2006, 08:21 | #36 (permalink) |
Insane Poster Join Date: Aug 2005 Location: Capetown, South Africa Age: 47
Posts: 97
Member: 169052 Status: Offline Thanks Meter: 121 | Basic Electronics ELECTRONIC BASICS Persons new to electronics can have difficulties with the component values and descriptions. Here are some guidelines for resolving these problems. a) Basics b) Resistors c) Capacitors d) Diodes e)Transistors f) IC's Basics The most often used terms in electronics are voltage and current To give you a metaphor for this you can think of a river. The voltage is the length of the river and the current can be seen the current of the river. This current is due the difference in height between the start and end of the river. One law you have to remember is law of Ohm. (See OHMS LAW). It is a simple law. Voltage = Current * Resistance or U = I * R Where voltage is in voltage [V], current in Ampere [A] and the resistance in Ohm. To make it easier for you to make conversions I will provide you [literally] a rule of thumb. Voltage [V] ------------------------------- Current [I] * Resistance [Ohm] Now just place your thumb over the unknown value and you will see what you have to do to find the value. For example. If you want the know the resistance then you have to divide the voltage by the current. Numbers can become quiet large in electronics. To prevent writing many zero's they use often different names. The following names are used. Value, milli-, micro-, nano- and pico- Example: Farad [capacitor] Farad, milli Farad [mF], micro Farad [uF], nano Farad [nF], pico Farad [pF] Every step is 1000 smaller like 1 Kg is 1000 Grams. Resistors Symbol ---/\/\/\/\---- or ------ ---| |----- ------ A resistor can be seen as a dam in a river. Water will have more difficulties to pass this dam. In a resistor this will result in the generation of heat. Resistors come in standard values to choose from. The value of a resistor can be found with the help of a colour table. The resistor has a set of coloured rings that will tell you its value. First ring : First number Second ring : Second number Third ring : Number of zeros to add Fourth ring : Tolerance [quality of the resistor. Mostly 5%] 1 Brown Examples: 2 Red 4700 Ohm 1 000 000 Ohm 3 Orange Yellow Purple Red Brown Black Green 4 Yellow 5 Green 6 Blue 7 Purple Brown Black Brown Red Red Red 8 Grey 100 Ohm 2200 Ohm 9 'White' 0 Black Values are often written as 10K, 1M or 4K7. This means in this case 10.000, 1.000.000 and 4700 Ohm. The 'K' just stands for Kilo and tells you that there is a factor 1000 there. The 'M' stands for mega and adds another factor 1000 Capacitors \ Symbol || ---||--- || A capacitor can have more functions but one of them is to store some energy in them. They act like a bucket. You can fill them with energy and drop the contents back when you need it. Values are often written as 10N or 2N2. This means in this case 10.000 and 2200 nano Farad. The 'N' just stands for nano. Small capacitors can have only numbers on them like 104. The first two digits is a number and the third digit tells you how many zeros you must add. In this case its four. The correct value of this component is 100 000 pF. [note: 100 nF or 0.1uF is also correct] Diode Symbol |\ | ___| \|___ | /| |/ | Diodes are the passive one-way locks in the river. Water can flow through them only in one direction. And only when there is enough difference in height [voltage]. Knowing this you may notice that a diode needs to have a direction to function. To show this there is a small mark at the casing. Normally this is a ring. For LED this isn't the case. You have to look inside and see the small plates. The one with the largest plate is the side where the 'ring' would be. Transistor Symbol | /c c = collector ___|/ b = basis b |\ e = emitter | \e These are the active locks in the river. They have a lock gate that can control the flow through them. They can also act like a switch. With a little current they can be opened and let a strong current pass. In the symbol there is also a arrow that will tell you the direction of flow. There are two basic transistor types namely; PNP and NPN. They are named to differentiate between different internal designs. A PNP has a symbol with the arrow pointing inwards and a NPN transistor has a arrow pointing outwards. IC (Intergrated Circuit) Symbol An IC doesn't have a universal symbol. It all depends on its use. A few examples are shown here. |\ +---+ ___| \___ -| & | | / -| |- |/ +---+ A little box that contains many small components as above. A complete circuit can be inside the black plastic casing. They have often 8, 14 or 16 pins. They are used for many purposes. The casing has a small notch on top of it or carved out of it. If you look at this mark and holding the mark on top then the first lead on the right side will be pin number one. Counting the pins downwards and continue at the first pin at the bottom at the other side. |
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05-04-2006, 04:42 | #38 (permalink) |
Junior Member Join Date: Jan 2006
Posts: 22
Member: 225561 Status: Offline Thanks Meter: 1 | http://rapidshare.de/files/17325655/..._bojs.rar.html this link its onlyy pay acu..... enybody please i needd for free download ????????????? |
05-07-2006, 11:26 | #40 (permalink) | |
No Life Poster Join Date: Mar 2003 Location: India Age: 73
Posts: 546
Member: 23587 Status: Offline Thanks Meter: 63 | Quote:
I can post my version of the same topics but yours is too good to be supplemented ! Regards | |
05-07-2006, 15:53 | #41 (permalink) |
No Life Poster Join Date: Jun 2005 Location: Punjab , INDIA
Posts: 1,260
Member: 153805 Status: Offline Thanks Meter: 325 | To understand mobile you must have basic Radio and some TV Knowledge. Think Mobile as a Digital Radio tuned to one station.In mobile incoming signal is amplified within ant. switch filtered by saw filters.which pass only narrow band off signal any unwanted signal is filtered out.then signal goes to RF ic were it is mixed with another signal which is generated locally in SHVCO and there difference which is lower than actuall signal is again filtered out in IF section and finally demodulated in RF ic.Incoming signal level is always not same it flactuate so AGC signal is generated (example in 3315 Cobba generates AGC signal).And SHVCO also tends to drift from its central frequency it is control by AFC signal (again generated by cobba) and keep it stable.In Radio all signals are analogue.In Mobile all signals are Digital.Mobile is a complex Radio.All functions are controlled by Software runned by CPU. |
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05-10-2006, 14:09 | #42 (permalink) |
Insane Poster Join Date: Aug 2005 Location: Capetown, South Africa Age: 47
Posts: 97
Member: 169052 Status: Offline Thanks Meter: 121 | Chapter 2 Soldering Techniques How important is soldering? Among the foremost of reasons an electronic project frequently fails to work properly is due to "poor" soldering practices. This is usually caused by "dry joints" when soldering. Here we discuss the correct procedures for soldering electronic projects. Dry joints when soldering At first glance many solder joints appear to be quite "O.K." but on closer examination many are in fact defective. The insidious problem with dry joints in soldering is that the circuit frequently performs alright for a period of time, even years before failure. This problem even occurs with manufactured equipment. Ask any TV / Video repair/Cell Phone technician who has torn a lot of hair out over an elusive fault ultimately traced back to a dry joint. Good soldering practices for your electronic project The cause of dry joints in soldering is mostly the improper application of heat. Both the component leg and the PCB need to be both heated simultaneously to the correct temperature to allow the solder to flow freely between BOTH surfaces. Obviously this requires practice and most newcomers inevitably get it wrong. Improper heating while soldering and its consequences can be seen below. Figure 1 - correct soldering procedures to avoid dry joints Here in figure 1 entitled "correct soldering procedures to avoid dry joints" we have three examples of soldering depicted. The first example indicates the component lead was heated while the PCB wasn't heated.As a consequence the solder only flowed onto the component lead. In the second example of soldering in figure 1 we find the PCB was correctly heated while little or inadequate heat was applied to the component lead. This is the most treachorous example because although I have made it very obvious in the diagram, in practice it is not always particularly obvious. Often this type of dry joint "just" allows the solder to "touch" the component lead while not actually being "soldered" to the lead. Of course it might work for a period of time depending upon environmental conditions of heat and cold. In the final example of "correct soldering procedures to avoid dry joints" We have depicted the solder bridging both the PCB and the component lead. In this case the PCB and the component lead were both heated "simultaneously" AND the solder was applied to either the component lead or the PCB to "flow" freely from one to the other to provide a good "electrical" joint. Such a joint is always "bright and shiny", dull looking joints are often suspect. You never apply the solder to the soldering iron "tip". Solder is always applied to the "job", never the soldering iron. Allow the solder to "set" and cool before proceeding to the next joint. Other cases of soldering We have discussed soldering components to a PCB yet this is not the only case of soldering. Often we need to connect wires to switches and other components. A common misconception is that soldering is designed to provide a good mechanical joint. - It isn't! Any connection should have it's own mechanical strength perhaps by twisting wires together or twisting the wire around a binding post or through a hole provided for the purpose. The solder is only intended for a good "electrical" connection. Never provide a connection which can't stand mechanically on it's own merits. What's soldering flux? Modern quality electronics solders contain a "flux" resin within the solder. This flux is designed to flow over the job and prevent contact with the atmosphere. Metals, particularly copper when heated tend to "oxidise" and prevent the alloying or good electrical bond between the copper and the solder. Good solder containing the resin will have resin flowing over the leads and prevent this oxidisation process and as the solder flows the resin is displaced allowing the solder to form an "atomic" bonding with the items being soldered together. A good resin helps to keep the surfaces clean. Rules for good soldering Of course some of these rules might seem very obvious but are worth repeating. Use a reasonable quality iron of the correct wattage for the job. Only use "electronic" resin cored solder of fine gauge. Make sure all surfaces to be soldered are "bright, shiny" and thoroughly clean. If a mechanical joint, make sure it can "stand alone" before soldering. Make sure the solder tip is clean, shiny and properly "wetted". Remember the soldering iron tip is only to heat up the surfaces to be soldered. Apply the resin cored solder to the heated "job", not to the soldering iron tip. Remember to visually inspect ALL of your soldered joints, preferably with magnifying glasses. Consider using your multimeter to provide an "electrical continuity" check between various parts of the circuit. |
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