Monday, October 31, 2005

Think Out Of The Box!

Well, yesterday's post was about modification of electronic circuit, and today I have another tips about modification. If you repair monitor i'm sure you have come across a dual diode part number which is the DMV32B or DMV56. In the package there is two diodes-one is the damper diode and the other is modulation diode. Most problems with this dual diode package is the modulation diode always developed a short circuit. If you can't find this part then you can modify it. Solder out the modulation diode pin and connect externally a ultra fast recovery diode-UF5408. How do i know if UF5408 diode can be use to substitute the modulation diode. Just go to the Dmv32b manufacturer which is the SG Thompson and download the diode data. From there you will know which type of diode is suitable for replacement. Even if the damper diode shorted, you may also look at the spec and find an equivalent number for it. But so far, I've never come across a damper diode shorted in the dual diode package. Hope from this tips you will be able to modify electronic circuits at the field you are in.

Sunday, October 30, 2005

Modification Of Electronic Circuit

Technologies changes very fast and we as a electronic repairer must be able to cope up otherwise we will loose our business. Take flyback transformer as an example-those days the flyback came with two knobs, one for the focus adjustment and the other one is for the screen voltage (G2). But now some of the monitor designed by Samsung, LG and etc the flyback came only with one adjustment which is the focus. So how are you going to adjust the screen voltage just in case the display is very dim?

Those monitors setting were set in the factory using software and after usage for certain amount of time the picture becomes dim and need to be adjust. The only way to adjust is to turn the screen voltage at the flyback transformer. Without the screen adjustment knob there is no way to increase the brightness unless you modify the circuit-but how? Due to this we as a electronic repairer besides know how to repair must also have the knowledge to modify the circuit because there is no way for the monitor manufacturer to release the software to us. By following the screen voltage (G2) cable from the CRT board you will be able to see some 'extra' circuit nearby the flyback transformer pin. By changing and playing around with the resistance value in this 'extra' circuit, i believe you will be able to modify it and the brightness will increase. It is a matter of time because there is so many type of circuit out there. After few modifications, you will be expert in solving dim display with only a single knob at the flyback transformer.

Saturday, October 29, 2005

Interesting Monitor Schematic Website

If you are in the monitor repair line then i have to recommend this fantastic Russian website about monitors. You can download for free all the schematics which include the LCD monitors. Remember to bookmark this monitor schematic website for future reference.

Friday, October 28, 2005

Lcd Monitor Back Light and Inverter Resources Website

If you repair lcd monitor then website is the good source for you. The company sell quite a number of products related to lcd monitor such as the back light and inverter. I've never bought any products from them but it was recommended by a professional monitor repairer named Ardell Faul who is very active in the monitor repair forum of the yahoo group. His tips on monitor repair are juicy and you will definitely learn a lot from him. Visit also for more information on lcd monitor back light and related components.

Thursday, October 27, 2005

If Possible Use Only The Original Component

Electronic components have many types of additional codes eventhough they are from the same part number. Those codes could represent date of manufactured, batch and version. Today's post i will talk about the last code that you often see it in a semiconductor. For example Horizontal output transistor BU2520AF and BU2520DF, both looks the same except the last code which is the AF and DF. AF means without damper diode while the DF have a damper diode in it. In some monitors both diode can be use but somehow in certain monitor design, only the original number that can last long. Which mean if i substitute the DF version with the AF version the monitor won't work long may be in only few weeks time. If you replace with the original number, you can expect the monitor won't come back for warranty claim! Substituting a component with an original number will give you a peace of mind. In certain cases where the original number are no more in the market then you are force to find a substitute. If possible get the exact part number with the same version. Here are few more example of components that you think it can be substitute with each other but actually cannot and will cause some weird symptoms in your equipment. TDA9109 is different from TDA9109/S, TDA1504 is different from TDA1504AP, LM1203N is different from LM1203BN, C5148 old batch is different from the new batch-it will cause the display to shrink after running for less than few minutes. Replacing the C5148 with the old batch solved the monitor power blink symptoms which is caused by the shorted horizontal output transistor C5148. From the facts above it is advisable to subtitute with original part number before look for substitution number.

Wednesday, October 26, 2005

Surface Mount Transistor

Yesterday's post was about the link to Martin Pickering's website on smd. Today i will share with you some tips on surface mount transistor cross. Surface mount transistor cross is valuable piece of information for every electronic repairer to find out what is the actual data in it. It could be a transistor, resistor, diode, capacitor or even a field effect transistor. Without knowing what the actual part is just like shooting in the dark. A wrong replacement not only cause the equipment to malfunction, it may also sometimes blow the surrounding parts. This is due to you have replaced the wrong part number with different specification. Surface mounted components often consist of more than one component in the single chip, such as transistors, base and bias resistors.

Leadless transistor chips
The surface mount transistor cross are represented on the board as a three legged triangle. Always find out the manufacturer's transistor drawings to determine what transistor has the base and collector, base and emiter terminals on one side. In most of today's electronic equipment, the leadless transistors have the base and emitter terminals on one side and the collector on the other side (middle). The transistors can have letters and numbers representing the value of the transistor, on top of the part. Remember, these components are very tiny and fragile (handle with care) and can easily be mistaken for a three legged diode. Confirm the main board and service manual for information on mounted compoenets.

Digital transistor chips
Nowadays you will find more digital transistors in many electronic equipments. The digital transistors are either NPN or PNP, with base and bias resistors.If you repair LCD monitor, you can find several different types of digital transistors. The two most common digital transistors used are PNP-DTA124EK with internal resistor of R1 (22 ohm) and R2 (22 OHM). The NPN type part number is DTC144EK with internal resistor of R1 (47 ohm) and R2 (47 ohm). Another number for NPN is DTC124EK with internal resistor of R1 (22 ohm) and R2 (22 ohm).

Testing surface mounted transistor
If the surface mount transistor do not have any internal resistor in it (which is very rare) then you can check the transistor the same way you checka bipolar transistor. An analog multimeter will do a great job in measuring transistor. However, if the surface mounted transistor consists of internal resistor just like the digital transistors, there is no way you can check it. This is due to the 'extra' resistance when measuring the transistor. Thus the reading that you get will not be accurate. The only way to test it is to swap another similar transistor with the same part number. After many years in electronic repairing line, i found that digital transistors are very reliable compare to the surface mounted type. Not only the surface mounted transistor are small, the part number sometimes are hard to recognize even with a magnifying glass. One more weakness about the surface mount transistor is that it can burnt easily when excessive current passed thru it. This will even make your repair work difficult as you could not see the part number. Even with the help of surface mount transistor cross there is no way to identify the component unless you have the similar model of the equipment with you.

Tuesday, October 25, 2005

Smd Components Resources

If you troubleshoot and repair equipment that uses a lot of smd devices such as the LCD monitor, satellite receiver, Tv, cpu motherboard, plasma tv and etc then this website about smd code is for you to refer. Martin Pickering is the well known author of many satellite repair book and his articles were published in Television Magazine every month. Browse thru his website and learn about troubleshooting electronic equipment in his forum. Visit his smd resources website now.

Monday, October 24, 2005

Flyback Transformer- How To Find The Primary And Secondary Coil

While surfing the net i came across this interesting website about how you can find out the primary and secondary winding of a flyback transformer using some circuit that is easy to understand. As i mentioned before in my previous post that i have to upgrade myself by reading, going to forum and surf the net. If i never surf the net then i would not found the website that i described above. Enjoy the flyback transformer website here!

Sunday, October 23, 2005

Beware of Low Quality Capacitor

I once bought capacitors that have no names and manufacturer code. Only showing the microfarad and the volt. The value that i bought was 1 microfarad 450Volt. I replaced it in the monitor circuit and when i switch on the monitor it blow immediately. I thought there must be some other components that cause the capacitor to blow. After thoroughly check each and every components i found all components at the high voltage flyback transformer side to be in good condition. I began to suspect the capacitor that i have changed. Replacing with another working capacitor taken from another good working unit proof that the capacitor that i bought in fact all were defective. Time are wasted checking this kind of fault which is actually very simple. I immediately asked for a refund from the supplier. The supplier said they also didn't know that the capacitor was indeed defective. If you use Esr meter to check you will surely see the different. The good capacitor have a lower esr ohms range while the defective one have a higher ohms reading. Strangely the capacitance value for the good and the defective one are quite the same. In future if you want to buy capacitors please check if the manufacturer name is printed on the side of capacitor. If there is no logo or other code please go to next electronic shop to find capacitors that have a logo and name on it.

Saturday, October 22, 2005

Electronic Repair- Don't Easily Give Up

Many times when comes to electronic repair, I'll sure met some tough dog (difficult) repair. New monitor design and circuit makes me have to keep up with my knowledge on this equipment. If I did not read books, magazine, visit forum and understand how this new design work then most probably I can't repair the monitor because you won't know where the culprit is. Some design are really complicated and makes you want to give up just by looking at the circuit. If you are well prepared, then you would not have to worry because if you know the principles you will know the rest. Can you imagine a technician have been repair analog monitor for many years and then digital monitor comes in and then lcd and then ......He have to learn how microcontroller works, how eeprom function, what is on screen display (OSD), how to troubleshoot digital controls and etc otherwise he would not be able to compete with his competitor. This is same for those who repair tv. Now the latest television trend is the plasma tv. Doing things alone also would not help you much. Talk and discuss with your repair friends about problems and solutions, latest news on repair, search the net, subscribe or buy electronic magazines. All these will definitely add knowledge to you. Remember, just don't give up and continue to improve yourself because learning has no end. I'm always motivated by this quote from Albert Einstein:

Friday, October 21, 2005

Power Supply Resources Website

If you wish to find any power supply related subject or information, then please visit this power supply resources website as it can help you to locate the information that you want.

Thursday, October 20, 2005

Electronic Magazines-Update News From The Manufacturer

Currently I'm only subscribe to two magazines which is the Nikkei electronic and Taiwan trade pages. These two magazines keep me update about the current technologies and latest innovation about electronic products. Both covered electrical manufacturing equipment, computer parts & peripheral, electronic parts and components, security & monitoring systems, telecom parts & equipment, wires, cables & accessories, catv/matv equipment & parts, mobile technology, wireless lan and many more. I used to buy Television magazine every month from my local bookstore but now they are no more selling. I called the distributor and they said there is no demand for this type of magazine. Every month there is so many copies left in the rack and the distributor have to return it to the main supplier. Peoples are now preferring the computer and gaming magazine. Well, time changes the trend! Even the famous Poptronics also have to stop publication due to low sales-and now they are selling the electronic information online. I noticed there is only few other UK electronic magazine at the rack and sometimes buried (covered) by popular magazines such as mobile, audio and etc. I did not buy those UK magazines because their content mostly on Programmable Logic Controller (PLC).
I don't know how to explain this but somehow deep in my heart I still prefer electronic troubleshooting and repairing magazine which is the TELEVISION magazine.
The TELEVISION is good because it covers the repair subject on DVD, vcr, TV, monitor, audio, CD player, testing equipment, home appliances, circuit theory, electronic component supplier, real life stories from fellow repairer and letters from the readers. In USA their famous magazine is the electronic servicing and technology and the information contributed by some of the well known electronic repairer such as Stephen j Bigelow and the late Homer L Davidson. Hope that you will buy or at least subscribe to some free electronic magazine. You can subscribe the nikkei magazine at this link here.

Wednesday, October 19, 2005

Electronic Repair Book's Website and Your Knowledge

I forgot to put the link to Sam's technical publishing website. Here is the Sam's publishing link again. Besides Sam's website you may try wiley bookstore to check out if there's any new technical book in the market. Books is so important to me, wherever i go i will bring along books with me. I read technical books, internet marketing, fishing magazine, natural healing and many more. If there is a heavy traffic i will just read books otherwise if you concentrate on the traffic you will get mad especially in the city of kl. Learning has no end, the more you read the more knowledge you will get from that subject. I still can remembered when i first got the homer l davidson tv troubleshooting book. I kept on reading for so many times and it never get bored and the more i read the more idea i get from his troubleshooting secrets.
If you want to be excel in your field read anyhting that relate to your field. I always tell my students that if you want to be a repairer then be the best repairer otherwise don't be a repairer at all. In order to succeed in your life, you need commitment and priority. If you go to work from 9-5 and then watch tv for the whole night, sleep wake up and go to work. You are in the cycle and please don't expect different result. For those who go extra miles such as taking night classes, read information relate to their work, surf net for new idea, keep on upgrading themselves or rather i call it move out from your comfort zone then they can expect different result. The results are so satisfying because you reap what you have sowed! If you plant an apple seed you get apple fruit same as our life, if you sacrifice your time to achieve your dream then you can expect it. Start improving yourself today, and the rest will be history.
Yesterday is history.
Tomorrow is a mystery.
And today? Today is a gift.
That's why
we call it
the present.

Babatunde Olatunji

Tuesday, October 18, 2005

Electronic Repair- Everyday's Life And Be Focus

Electronic troubleshooting can be fun and frustrating also especially when you could not locate the culprit. Time don't wait for you. You are given only 8- 9 hours a day to do the repair job. More or less equipment can be repair depends on the speed and the knowledge you have about electronics. My answer is focus-you can repair any or every electronic equipment but your knowledge toward all the equipment is not much. You loose concentration easily and the success repair rate is not high. There is one saying "Jack Of All Trade But Master Of None". Specify what are the equipments that you want to repair. As for me i have chosen monitor and power supplies repair. I've never look back and equip myself with only power supplies and monitor knowledge. I've a lot of customer who asked to repair cd rom, Tv, dvd, Vcd and etc. I told them that i only concentrate on monitor and power supplies repair. Just these two equipments already took up my entire time. New design launch almost every weeks and i have to cope up with the trend and technologies.
Those days were analog monitors and now is digital with on screen display (OSD) and then tft and lcd. It never end and sometimes quite tiring to actually follow what is the latest model, design and circuit like. Not only that, you have to subscribe or buy electronic magazine and books and also visit forums to update your knowledge in electronic repair. Imagine i'm also repair other equipments then my whole life would be drawn to all the updates of equipments- no spare time for my family.
I've a repair friend who repair all sort of electronic equipment, if you go into his workshop you can be lost and dare not send things for him to repair. Why? The TV's board, monitor cover, vcd changer, transformer, hi-fi speaker and other things scattered all around his workshop. Unless he spend his time to keep all the things tidy but i can see he has no time because he tried to repair all kind of electonic equipments. He even sent some monitors for me to repair with simple faults. He worked everyday until midnight and no time for other matter. Don't get me wrong, if you are well prepared and have enough resources carry on with your idea of repair more than one equipments. Some would say don't put all eggs in one basket. Because of this i diversified into teaching line and internet marketing. I still do monitor repair in my workshop and if there is class i will teach. At night i'm in full strenght on internet marketing. That's why you can see i've time to write my blog and articles for Have a nice day!

Monday, October 17, 2005

Esr meter and Flyback tester

When i started the monitor repairing business back in 1996, i have limited knowledge about testing equipment. The only equipments that i had is analog meter, digital capacitance meter and digital meter. The success repair rate for me is 7-8 out of 10. Some i really do not know what was the cause of the problem. The internet on that time was still new and i still can recalled the only technical website that i like to visit was the sam goldwasser website the well known technical repair writer. My free time i usually read technical books by some famous technical authors such as Homer L Davidson (my favorite author), Stephen J Bigelow, Art Morgalis, Robert L Goodman, John G Stephenson & Bob Cahill(microcomputer troubleshooting & repair by SAMS) and many more.

They are fantastic in sharing their knowledge in electronic repair. I always remembered a quote by jim kocmoud "knowledge is never knowledge until you share to someone who needs it". Recently i went to a local book shop to scan thru if there is any new books on electronic repair-i got a shocked after seeing a back cover mentioning Homer L davidson had passed away. I'm sad as he is one of my best repair guru in my life. The books that he had written was marvelous and i have to admit that i learned a lot from his experiences. This are the people that we have to salute because he never kept his repair secrets to himself, he revealed everything he knows about electronic repair. He passed on his knowledge to the next generation.

Back to the meter, i purchased bob parker's esr meter and lopt or flyback tester in the year of 1999 if i'm not mistaken. These two meters are a gem to me as both meters have solve a lot of tough dog problems for me. Then i proceed to buy another version of esr meter which is the Cap analyzer 88A. Both meters are so good in locate capacitor fault while still in circuit. The repair rate had shoot up to 9 and sometimes 10 out of 10. Realizing that meters can actually help you out in electronic repairing, more meters are bought such as muter regenerator crt tester, huntron tracker, atlas transistor tester, oscilloscope and etc.

If you want to be successful in electronic repairing line don't try to stop from investing on testing equipments. They can actually speed up your repair job and make fast money and the equipments can be pay back by itself in a very short time. If you are on budget try visit to check out any cheap and good equipment for sale. You will be glad to have some good and reliable testing equipments by your side. To me testing equipments is just like another helper. I have no regret in investing so much on them. Well this is one of my secrets in electronic repairing.

Sunday, October 16, 2005

Anatek Corporation For Sale

It was quite a surprised to know that the well known anatek corporation is for sale.The company established since in the early 90's and i believe most of the electronic repairer throughout the whole world knows about According to the website, the owner john bachman wants to retire and ready to make a good deal with the right person. I've known john and his wife pamela when i started to join their repair group where they charge a monthly fees. I have to say that the electronic repair forum is my greatest help in my life as a electronic repairer. Those super tech in the forum was fantastic and most of the questions that i post was answered by them. The good old memories that i've with them are kurt hannson, jeff robert, derek cook, jim kocmoud, allen yung,wee k chew,tom cadwallader, william braell,hector scaramelli and many mores. They are very active in the repair forum and willing to help any newbies in electronic repair.
The monthly fees is easily pay back by itself. The electronic repair knowledge that i acquired from this forum is beyond i can describe. I joined since 1998 or 1999 till 2002. John Bachman was very helpful and kind in answering our questions. His wife Pamela incharge on the payment. In early 2004 i had a joint venture with them but things don't work out really good due to my side of unable to handle software problem after my webmaster resigned. I was totally blanked when my webmaster resigned from her post. It took me months to learn about web design and finally i'm able to slowly manage to handle my website which is I wish them all the best and may God bless them always.

Saturday, October 15, 2005

Electronic Troubleshooting-Past, Present and the Future

I started quite young at about the age of probably 8 or 9 years old. Something inside or rather i call it curiosity, i begin to dismantle electronic toys, and play around with torch light, batteries, light bulb, wiring, and whatever i think have some relation to electronic. Most of the electronic repairer that i knew also start from very young, however some of my repair friends begin to like electronic when they are in the college. That's when their parents want them to take the engineering course. During the 80's i can say many school leavers look for the engineering courses. Time have changed where most of the school leavers nowadays prefer computer related courses such as programming,web design and etc. Out of ten parents that i asked about what are the course their sons or daughters studying-7 or 8 of them will answer computer courses! That's why in these days engineering schools are getting lesser and lesser while computer related courses is booming. I do not know how long this electronic related field can sustain as most of the electronic equipments nowadays are so cheap such as the vcd and dvd. Look at VCR, you seldom heard of it anymore compare to other video equipment. It is not your experience that fade you out, it is the technologies that keep you out of business. Things are getting smaller and cheap and hard to repair also. Suppliers nowadays don't carry much stock and this add salt to our injury. Setting up this blog hope that it can help us to come together to discuss the problems and solutions about electronics-remember you are not alone out there and we would like to hear from you.

Friday, October 14, 2005

Electronic Repair and Troubleshooting Tips

This is my first electronic repair blog and I decide to write about my experiences in electronic troubleshooting. For those of you who are interested in electronic repair hope that you will learn a lot from my years of experience in electronic repairing. Feel free to drop by and check out any latest news related to repairing. You may also bookmark my blog for your daily reference. I will do my best to share whatever i know about electronic repair to you as i believe the more you share the more you will learn. The subject that i will cover are testing electronic components, testing equipment, new electronic troubleshooting gadgets, news from electronic manufacturers, tips in repair, new electronic repairing website, electronic repair books and magazine, problems and solution in monitor repairing, a little bit on my personal life and internet marketing. Since my main line is in monitor repairing and if i can't give you the answer on other electronic subject, i will direct you to certain website or forum and hope they will help you out. Currently i'm writing 2 to 4 electronic repair articles every week at my homepage Subscribe the newsletter and if i have any new article you will be notify thru email. All the best.
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