| |
| |
|
Hardware Information |
|
|
|
Testing Flyback Transformer - How to Test and When to Replace It
Nowadays, more and more monitor comes in with flyback transformers problems. Testing flyback transformers arenot difficult if you carefully follow the instruction. In many cases, the flyback transformer can become short circuit after using not more than 2 years. This is partly due to bad design and low quality materials used during manufactures flyback transformer. The question is what kind of problems can be found in a flyback transformer and how to test and when to replace it. Here is an explanation that will help you to identify many flyback transformer problems. There are nine common problems can be found in a flyback transformer: a) A shorted turned in the primary winding. b) An open or shorted internal capacitor in secondary section. c) Flyback Transformer becomes bulged or cracked. d) External arcing to ground. e) Internal arcing between windings. f) Shorted internal high voltage diode in secondary winding. g) Breakdown in focus / screen voltage divider causing blur display. h) Flyback Transformer breakdown at full operating voltage (breakdown when under load). i) Short circuit between primary and secondary winding. Testing flyback transformer will be base on (a) and (b) since problem (c) is visible while problem (d) and (e) can be detected by hearing the arcing sound generated by the flyback transformer. Problem (f) can be checked with multimeter set to the highest range measured from anode to ABL pin while (g) can be solved by adding a new monitor blur buster (For 14' & 15' monitor only.) Problem (h) can only be tested by substituting a known good similar Flyback Transformer. Different monitor have different typeof flyback transformer design. Problem (i) can be checked using an ohm meter measuring between primaryand secondary winding. A shorted turned or open in secondary winding is very uncommon. What type of symptoms will appear if there is a shorted turned in primary winding? a) No display (No high voltage). b) Power blink. c) B+ voltage drop. d) Horizontal output transistor will get very hot and later become shorted. e) Along B+ line components will spoilt. Example:- secondary diode UF5404 and B+ FET IRF630. f) Sometimes it will cause the power section to blow. What type of symptoms will appear if a capacitor is open or shorted in a flyback transformer? Capacitor shorted a. No display (No high voltage). b. B+ voltage drop. c. Secondary diode (UF5404) will burned or shorted. d. Horizontal output transistor will get shorted. e. Power blink. f. Sometimes power section will blow, for example: Raffles 15 inch monitor. g. Power section shut down for example: Compaq V55, Samtron 4bi monitor. h. Sometimes the automatic brightness limiter (ABL) circuitry components will get burned. This circuit is usually located beside the flyback transformer. For example: LG520si Capacitor open a. High voltage shut down. b. Monitor will have 'tic - tic' sound. Sometimes the capacitor may measure O.K. but break down when under full operating voltage. c. Horizontal output transistor will blow in a few hours or days after you have replaced it. d. Sometimes it will cause intermittent "no display". e. Distorted display i.e., the display will go in and out. f. It will cause horizontal output transistor to become shorted and blow the power section. How to check if a primary winding is good or bad in a Flyback Transformer? a) By using a flyback/LOPT tester, this instrument identifies faults in primary winding by doing a 'ring' test. b) It can test the winding even with only one shorted turned. c) This meter is handy and easy to use. d) Just simply connect the probe to primary winding. e) The readout is a clear 'bar graph' display which show you if the flyback transformer primary winding is good or shorted. f) The LOPT Tester also can be used to check the CRT YOKE coil, B+ coil and switch mode power transformer winding. NOTE: Measuring the resistance winding of a flyback transformer, yoke coil, B+ coil and SMPS winding using a multimeter can MISLEAD a technician into believing that a shorted winding is good. This can waste his precious time and time is money. How to diagnose if the internal capacitor is open or shorted?By using a normal analog multimeter and a digital capacitance meter. A good capacitor have the range from 1.5 nanofarad to 3 nanofarad.* 1) First set your multimeter to X10K range. 2) Place your probe to anode and cold ground. 3) You must remove the anode cap in order to get a precise reading. 4) Cold ground means the monitor chassis ground. 5) If the needle of the multimeter shows a low ohms reading, this mean the internal capacitor is shorted. 6) If the needle does not move at all, this doesn't mean that the capacitor is O.K. 7) You have to confirm this by using a digital capacitance meter which you can easily get one from local distributor. 8) If the reading from the digital capacitance meter shows 2.7nf, this mean the capacitor is within range (O.K.). 9) And if the reading showed 0.3nf, this mean the capacitor is open. 10) You have three options if the capacitor is open or shorted. - Install a new flyback transformer or - Send the flyback transformer for refurbishing or - Send the monitor back to customers after spending many hours and much effort on it. * However certain monitors may have the value of 4.5nf, 6nf and 7.2nf.Note: Sometimes the internal capacitor pin is connected to circuits (feedback) instead of ground. Tv rca flyback transformer circuits usually do not have a internal capacitor in it. If you have a flyback diagram and circuits which you can get it from the net, that would be an advantageto easily understand how to check them. Jestine Yong is a electronic repairer and a writer. For more electronic repair articles please visit his website at http://www.noahtec.com/electronic-repair-articles.htm
MORE RESOURCES:
Audio-Streaming - Google News |
|
|
|
RELATED ARTICLES
Facing DVD Software Dilemma? Its Brainlessly Simple 1. Pocket DVD Wizardhttp://www. Getting A New Laptop At A Great Price With all the wheeling and dealing that seems to take place on the internet at all times of the day, it can sometimes get confusing just trying to find your own deal. Finding the best price on your new laptop is most likely your highest priority at this point, but there are other important factors as well. Toner Cartridges - How They Work In the past computers and their accompanying printers were huge. Toner reservoirs and toner cartridges were used instead of ink cartridges like the ones in use today. Testing Capacitor-How To Test A Capacitor When Breakdown Under Load Have you ever come across power problem where onceyou switch on the power supply and the fuse blow? Youhave checked all the components in the power (primary)and secondary section and all the components seems to beok! Where is the fault? A fuse blown are usually causedby a shorted bridge rectifier, defective posistor, powertransistor or FET, shorted primary winding of switch modepower tranformer, shorted secondary diode and etc. Butin this article i'm gone to show you another secret of electronic troubleshooting tips. A Short Introduction to Blu Ray Blu ray is a next generation optical media format developed by the Blu ray disc association, a group of leading consumer electronics and technology companies such as Apple, Mitsubishi, Panasonic, Philips, Samsung, Sony, TDK to name, but a few.The format was developed for high definition video, as well as storing large amounts of data. Selecting a Laptop Small Can Be BeautifulWhen purchasing a new computer, you may be better served by a laptop than a traditional desktop computer. Recently, laptops with capabilities similar to desktops can be purchased for a comparable price. Laptop Computers and the PVP Effect! Roll over lumbering desktop computers, the limber laptop is here, and it's here to stay! For a while now notebooks have outstripped their ageing desktop PC siblings, easily winning the gold medal in the computer sales olympics. We will illustrate how the PVP effect has contributed greatly to the increase in popularity of notebook computers. Ten Things Everyone Should Know about Ordering an Inkjet Cartridge Online It is true. You can save a lot of time and money by ordering your next inkjet cartridge online. What Can You Do With A Mac Mini? If you have not seen the newest addition to the Macintosh line, it is worth taking a look. It is a very small computer that is only 6. Whats In An LCD Display? Who needs an LCD display? Well, if you're like me, having one huge hunk of a monitor sitting on your desktop is just not feasible. Not only does it take up desk space, but there's just simply no need for all of the physical mass, right?Welcome LCD displays-the computer monitors of the present and future. The Importance Of Current Sense Resistor In Switch Mode Power Supply Current sense resistor is usually located in the switch mode powersupply section. Newer version of monitor-the b+ (boost) circuitalso have this current sense resistor. Ten Ways (plus 1) to Save on Printer Ink and Toner Cartridges Are you getting tired of the high cost of printing? You're not alone. Many consumers are up in arms. The Printer Cartridge Wars: Generic or Remanufactured Cartridges Right for You? OverviewAs "generic", "remanufactured", and "new compatible" inkjet printer cartridges and laser toner cartridges creep deeper into the printer accessories market, the choices become varied and often confusing. It is estimated that by the year 2004 the aftermarket share of the inkjet and toner cartridge market will exceed 11% of the estimated 12 billion dollar printer accessory market [source: CART magazine, March 2001] Here's a look at what all these terms mean, and an examination of the upside and downside of using non-"brand name" printer cartridge products in your printer. Hard Drive Selection Perhaps the biggest mistake people make when building their computer(s) is to underestimate the importance of the hard disk drive (HDD). In our modern society, bigger is synonymous with better, so when you go to buy a hard drive you look at how "big" it is, its data capacity. ESR Meter - The Capabilities To Check Beyond Electrolytic Capacitor There is something good about esr meter because besides electrolytic capacitor it can be use to measure other type of capacitors such as the non polarity capacitor. From esr meter specification, it is usually mentioned only checking the electrolytic type. Top Three Factors to Consider While Choosing a Data Center for Your Business Data Centers are the core of the Internet. The computer servers that power the Interne,t call Data Centers their home. Used Laptop Computer: Your Quick Purchase Inspection Guide - Part 2 Used laptop computers are everywhere these days. How can you sift through the mass of available used laptop computers to narrow your search down to the right laptop for you? This is the second part of a series of articles designed to give you a few suggestions for your next purchase. 10 Things to Ponder Before Moving Your Office Network Moving the office network? How hard could it be? Anybody who's ever moved the office network knows the risks and challenges associated with this colossal task. This mighty endeavour is not merely a case of logging-off, shutting down and pulling the plug. Choosing a Tape Drive Tape drives remain the leading technology used by organizations for backup and archiving. However, the plethora of tape drives on the market can make choosing the appropriate tape drive a confusing task. High Definition DVD High definition DVD, also known as HD-DVD (which actually stands for High Density DVD), is one of two competing high definition storage format - the other being Blu-ray.The need for a new, high capacity storage format, has been primarily brought about by the rapid rise in popularity of HDTV in Japan and the US.
|
|
|
Top of Page home | site map home Bookmark Us Now ctrl+d 1st 4 Games, shopping via this site cost no more than going direct and can often save you money with special offers. |
