This DELL 17” Monitor (Made in Malaysia under LIKOM model L705XXX, product no: L7055LP) came in with no power symptom. Normally after opening up the cover I would look at the power supply (primary side) for any burnt and cracked components first. If there are darkened area and burnt components, I would tell myself that this Monitor needs a little more time to repair it. If it is not (component’s intact) I would usually begin to discharge the filter capacitor and start checking the fuse.

Okay, it is confirmed that all the primary side components looks good in this Monitor.

First, discharge the big fat filter capacitor with a resistor (I know that the voltage already drained off but it is a normal procedure for me because what if the start up resistor has an open circuit?) then check the fuse.

If the fuse is okay, experience will tell you that the bridge diodes are also working fine. Place your black probe of your analog meter set to x1 to the center pin (drain) of the power FET and red probe to the other pin one at a time (gate and source). If the pointer of the meter doesn’t kick then 80 % of the Power FET is okay. If you want to 100% confirm if it is good then you have to solder it out and test. If the pointer shows a reading then most probably the power FET has developed a short circuit. The result that I got from this Monitor was the pointer don’t flick.

Now is the time for me to use the dick smith flyback tester to check the smps primary winding. The result that I got was, the led bar don’t lit. Ah ha! That was a clue and this clue tells you that it is either the smps primary winding is shorted or one of the secondary diodes has given way. Of course you can check all the secondary diodes with your normal multimeter first (remember, every electronic repairers have their own procedure methods of troubleshooting) but I prefer this way as I want to confirm also if the smps primary winding is working or not.

Usually smps transformer is very robust thus I didn’t suspect it to pull down the flyback tester reading. I straight away check all the secondary diodes with my analog meter and found one diode shorted (part number U202G). Since I do not have this part number, I use a UF5404 ultra fast recovery diode as a replacement. In fact I use this UF5404 to all 14 to 17” Monitor as a replacement for all part number of secondary diodes. The spec of this diode was 400volt, 3 Amp with 50 nanosecond.

After the replacement of the diode, and placing the flyback tester probes again to the primary winding, the result shows full bar on the LED. Don’t be happy with the result yet because your job still hasn’t done.

Now I moved on to check HOT with the same procedure as checking the power FET. The HOT checked to be okay too. Next, I check the internal capacitance of the flyback transformer to see it is shorted or not or is the capacitance value run. For your information, internal capacitor in flyback transformer gave lots of problems in computer Monitor. I also scanned thru the B+ FET and found it to be good too.

Now is the time to switch on the Monitor, however this round I don’t connect any bulb because it was only a shorted diode in the secondary side. I would only connect a light bulb after repair when there is major short circuit in the primary side such as a blown bridge rectifier, shorted fet and smps primary winding and also burnt components in the board.

The ECG cross reference signifies an ECG replacement directory, which lists more than 300,000 manufacturer house numbers, and these numbers are cross referenced to ECG types that can replace them. The directory, which started with a list of semiconductors, soon included other products as well.

The ECG line of semiconductors was originally conceptualized by Sylvania before Philips took over the company, and though these semiconductors were originally targeted at the secondary markets, they soon found their way into the industrial repair and maintenance departments. The ECG cross reference is a great help in looking up U.S. and foreign manufacturer numbers and thereby identifying the device type, printout and other relevant information. The greatest advantage of the ECG cross reference is the amount of time saved without searching through catalogues or hunting for manufacturers.

The ECG cross reference constitutes a long list that is quite comprehensive. This includes transistors, diodes, and ICs, silicon bilateral switches (SBS), Silicon unilateral switches (SUS), Silicon asymmetrical switches (SAS), and bilateral trigger diodes (DIACS). Soon, semiconductor devices such as JFETS, MOSFETS, and IGBT were added. Multipliers, rectifiers and other such high voltage devices also found themselves in the list. Transient voltage suppressors, quartz crystals, linear and digital integrated circuits and optodevices have now been added to the ECG series. With advancement of information technology and increased use of computers and related accessories, the ECG line has microprocessors, memories, IC interfaces and even surface mounted components. The ECG product line now includes environment-friendly chemicals, digital multi-meters, surge protectors, flyback transformers, flameproof resistors, antenna rotators and rechargeable batteries.

Digital Imaging is a process where an electronic photograph, scanned document, or image is converted into a series of electronic dots called pixels. Pixels is an acronym for “picture elements”.

After the image is converted, or digitized, it is stored on a memory storage device which may be a hard drive or some sort of electronic storage device such as a memory stick. The pixels are stored in a compressed format to save storage space.

As each pixel is being created it is assigned a color value, called a tonal value, of black, white, shades of grey, or an actual color. These pixels must be processed by a piece of software in order for them to be called up and viewed as an actual image later.

Traditional cameras capture images onto film while digital cameras use an electronic chip known as a Charged Coupling Device (CCD). The CCD is actually a grid of miniature light-sensitive diodes. These diodes convert photons (light) that strikes them into electrons (electrical impulses). The technical name for these diodes is ‘photosite’. The brighter the light is that hits the photosite the stronger the electrical charge is that’s produced.

After converting the photons into electrons, a mini-computer, located inside of the camera, reads the stored electrical value in each photograph. Then a built-in analog-to-digital converter turns the stored electrical value into a digital value. These digital values are then stored on the cameras memory storage device. When these digital values are recalled by software, and displayed on a screen, they reproduce the image that was originally captured by the camera or digital input device.

The digital image that is created by the CCD is huge. It’s far too big to be easily stored in the relatively little amount of storage space that’s available to a digital camera. Accordingly, the camera’s computer compresses the image to make it smaller.

There are two basic methods for achieving this compression. The first method takes advantage of repetitive patterns in the image. For example, if you are taking a picture of an airplane that is flying in the sky, a lot of the picture will be a chunk of blue sky. The camera recognizes that there are multiple parts of the image containing the same digital information, so it only records a small piece of the sky. Then it simply creates a map to tell it where the rest of the sky belongs. When the picture is ultimately displayed the sky appears exactly the same as it did in the original image when it was first captured. The only difference is that the overall storage requirements were reduced thanks to the camera’s clever mapping techniques.

Companies that design, assemble, produce, and test electronic components and assemblies for original equipment manufacturers are known as electronic manufacturing services.

The original equipment manufacturers, commonly termed as OEMs, retain the ownership of the said product designs and brand names. Electronic Manufacturing services sometimes branch out into contract electronic manufacturers, and specialize in rapid prototyping and product testing.

Electronic manufacturing services offer large, small or medium production runs. The materials can be built from consignment, vendor-owned or customer supplied materials.

Some electronic manufacturing services offer design services like conceptual product development advice, software, and mechanical and electrical design assistance.

Various other electronic manufacturing services have testing abilities and can perform in-circuit, environmental, functional, analytical laboratory and agency compliance testing.

They use several processes and manufacturing technologies. Some of them provide printed circuit boards, connected populated boards or assembly services into larger assemblies. Other products that can be made are flexible printed circuit boards, rigid boards and rigid-flexible circuit boards.

Some vendors specialize in optoelectronics. They can assemble devices that will function as electrical to optical or optical to electrical transducers. Light emitting diodes, injection laser diodes, and photodiodes can also be assembled.

Electronic manufacturing services also include component mounting. The electronic manufacturing services use two basic technologies, through hole technology (THT) and surface mount technology (SMT).

In the THT, components are mounted on a PCB by inserting component leads through holes in the board. They are then soldering the leads in place on the opposite side of the board.

DPSS laser modules are the most used types of lasers for both industrial applications as well as personal enjoyment. The term DPSS, diode pumped solid state, refers to the state of the laser diode as it produces its laser beam through its collimated laser crystal. The complexities of designing and modding lasers of this nature have pushed scientists and light engineers to design brighter and more powerful solid state lasers, from hand held pointers to large box laser units.

There is clear value in the use and application of certain laser products, no more so than in the use of industrial laser modules. Lasers are relatively new technology, and for this reason, there is constant advancement and improvement of both the design and performance of lasers for their specific said use. The most common forms of industrial laser use include laser engraving, laser cutting, laser burning, and more. The versatility of condensed laser light allows for a broad spectrum of valuable scientific and industrial based applications. Various laser beam color frequencies can be utilized, as each different wavelength will produce a different color, visible or invisible, that can then be tuned to be geared towards a specific use.

But what is the real difference between DPSS laser modules and your average laser pointer? There are clear differences both in design and in performance capabilities. For instance, dpss laser diodes require an external power source and must therefore be plugged directly into a walls electrical source or be attached to a laser “battery” for ignition. This poses a few problems if you are looking to perform any experiments in the outdoors or in the field, where plugging the laser in is impossible. The industrial laser diodes are usually far larger than laser pens as well, because many of them require internal thermoelectric cooling because of the heat produced by the solid state laser beam.

Laser pointers, on the other hand, are extremely convenient in size and shape, but may lack the same performance consistency as large boxed diodes. Also, industrial laser applications are nearly impossible for a laser pointer because the high-tech device must be manually engaged and even held in one’s hand. This can make cutting and engraving all but impossible, not to mention most laser pointers are not capable of producing enough mW (milliwatt) power to complete the desired industrial task. Pointers are more geared towards laser presentations, astronomy, and even just simply laser pointer fun. There is no question that industrial dpss laser modules have found a strong standing amongst many industrial professionals around the globe, be sure that you are working with certified laser modules from a reputable dpss industrial laser retailer. You would not want to sacrifice a few dollars to buy a laser online that simply won’t accomplish what you are looking for.

Diodes Incorporated (Nasdaq:DIOD), a leading manufacturer and supplier of high quality discrete semiconductors, today announced the release of two new lines of precision Zener diodes. The new Zener lines are the second and third product releases utilizing Diodes-FabTech’s breakthrough precision, high velocity ion implantation process.

Most Zener diode products available on the market today are the result of a traditional diffusion-based process and result in tolerance on Zener breakdown voltage (VZ) down to approximately +/-5% at high yield. In contrast, Diodes’ ion implantation process is highly targeted and enables significant performance improvements with control over VZ tolerance to +/-2% at very high yield and can achieve tolerances down to +/-0.5% if required.

“With these new additions to our Zener line, we continue to leverage our proprietary ion implantation process to push the envelope of device performance and deliver greater value to our customers,” said Mark King. “Zener Diodes are a key component of our sales mix and these new additions mean that we are now able to offer one of the most comprehensive Zener portfolios in the industry.”

The new ultra tight tolerance Zener product line is the DDZ series, and is packaged in a variety of miniature and sub-miniature SOT (3 and 6 pin) & SOD (2 pin) surface mount packages. The series will be marketed as a superior alternative to several popular existing Zener diode lines including the 5200 series, BZT52, and BZX84 series. The DDZ line expands Diodes’ application specific array portfolio, specifically targeting price and space sensitive handheld and battery powered applications requiring no-frills voltage regulation.

The ion implantation technique is also being utilized to produce the new DDZ9600 series featuring a low Zener test current of 50 microAmperes. Optimized for operation at very low biasing currents, the 9600 series is ideally suited for use in portable end products requiring a minimum of power consumption for extended battery life, such as notebooks, mobile communication and hand-held computing devices, including PDAs.

Both the DDZ series and the DDZ9600 series are initially offered in SOD-123, SOT-23, SOD-323, SOT-323 and SOT-363 packages and are assembled at the Diodes-China facility. Initial voltage offerings range from 5.1 Volts to 43 Volts for DDZ and 2.7 Volts to 39 Volts for DDZ9600 with planned expansion down to 3.6 Volts for DDZ and 2.4 Volts for DDZ9600 by 4Q03.

About Diodes Incorporated

Diodes Incorporated (Nasdaq:DIOD) is a leading manufacturer and supplier of high-quality discrete semiconductor products, serving the communications, computer, industrial, consumer electronics and automotive markets. The Company operates three Far East subsidiaries, Diodes-China (QS-9000 and ISO-14001 certified) in Shanghai, Diodes-Taiwan (ISO-9000 certified) in Taipei, and Diodes-Hong Kong. Diodes-China’s manufacturing focus is on subminiature surface-mount devices destined for wireless devices, notebook, flat panel display, digital camera, mobile handset, set top box, DC to DC conversion, and automotive applications, among others. Diodes-Taiwan is our Asia-Pacific sales, logistics and distribution center. Diodes-Hong Kong covers sales warehouse and logistics functions. The Company’s 5″ wafer foundry, Diodes-FabTech (QS-9000 certified), specializes in Schottky products and is located just outside Kansas City, Missouri. The Company’s ISO-9000 corporate sales, marketing, engineering and logistics headquarters is located in Southern California.

Safe Harbor Statement Under the Private Securities Litigation Reform Act of 1995: Any statements set forth above that are not historical facts are forward-looking statements that involve risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. Potential risks and uncertainties include, but are not limited to, such factors as fluctuations in product demand, the introduction of new products, the Company’s ability to maintain customer and vendor relationships, technological advancements, impact of competitive products and pricing, growth in targeted markets, risks of foreign operations, and other information detailed from time to time in the Company’s filings with the United States Securities and Exchange Commission.

Carbon-composite submounts tipped with diamond are being developed as improved means of dissipating heat generated in high-power laser diodes. Copper is the traditional heat-sinking material for many applications other than laser diodes; it is not suitable for heat-sinking submounts for laser diodes because its coefficient of thermal expansion (CTE) is too high to enable an acceptably close match to the CTEs of laser-diode semiconductor materials. Heretofore, heatsinking submounts for laser diodes have been made from a copper/tungsten alloy, chosen because of its rigidity and its low CTE, which matches the CTEs of the laser-diode semiconductor materials more closely than copper does. Unfortunately, the thermal conductivity of the copper/tungsten alloy is only 45 percent of that of copper. In contrast, the carbon composites of the present development can be made to have both low CTEs and effective thermal conductivities of the order of three times that of copper.

The carbon-composite materials under consideration in the present development effort include, variously, graphitic or vapor-grown carbon fibers in matrices that comprise one or more other forms of carbon and that can include diamondlike carbon. Metals (typically, copper or aluminum) can be used as alternative matrix materials to increase effective thermal conductivities. Like other composite materials, these composites can be formulated to tailor their thermal and mechanical properties within the limits imposed by the intrinsic properties of the constituent materials.

The thermal conductivities of these composites are much higher in the along-fiber directions than in the cross– fiber directions. This anisotropy must be taken into account in designing a heatsinking submount, as in the example illustrated in the figure. The laser diode is mounted on a wedge made of either chemical-vapor-deposited diamond (which has about twice the thermal conductivity of copper) or single-crystal diamond (which has about five times the thermal conductivity of copper). The diamond wedge conducts heat away from the laser diode. The slanted face of the diamond wedge distributes some of the heat to a mating carbon/carbon composite wedge that contains horizontal fibers and that conducts this portion of the heat into a main carbon/carbon heat-sink body that also contains horizontal fibers. The slanted face of the diamond wedge also distributes some of the heat downward into a larger carbon/carbon composite wedge that contains vertical fibers. These vertical fibers meet the horizontal fibers of the main heat-sink body at mating slanted wedge surfaces. The heat-sink body conducts the heat away horizontally. The far end (the right end in the figure) of the heat-sink body is placed in contact with a heat pipe, radiator panel, or other suitable heat sink.

Offering an extremely low EMI, the 8EWF06S and 8EWF12S soft recovery rectifier diodes from International Rectifier are optimised for low forward voltage drop and reverse recovery times of 50 and 80ns.

These 600 and 1200V diodes are offered in a D-Pak with current ratings of up to 8A. The maximum operating junction temperature is 150 degrees C, and each device features glass passivation which ensures high reliability levels and long-term stability.

Link Microtek has launched the LSZ series of zero-bias surface-mount Schottky diodes, which suit use in commercial wireless applications such as up or downconverters and phase detectors.

Made by Microsemi Microwave Products, these microwave discrete semiconductor devices use an SOT-23 plastic package and are supplied taped and reeled ready for mounting by automatic pick and place machines.

The diodes can be specified in a choice of single reverse right or series.

Crydom International has introduced TVS diode protection on its range of SSR products. TVS diodes are fitted internally and shield the entire product. This is said to make the entire process of installing the company’s SSRs easier, as users are not required to fit any extra parts.

With integral shielding the range of SSRs are claimed to be more reliable and help extend the lifespan of the product.

An LED status indication has also been included. This function allows the user to see at a glance whether the SSR is functioning; a green LED displays when power is present at the input.