Apr 29, 2017 power supply troubleshooting and repair tips duration. Switching power supply fundamentals there are two basic types of pulse. A bridge rectifier can be normally seen at the beginning of any smps circuit and is introduced primarily for rectifying the mains ac to a full wave dc, which is further filtered using a filter capacitor and applied to the mosfetinductor stage for the intended flyback primary side switching operation. If you had measured all the components in the power supply section and could not find the defective component, then try troubleshoot components beyond the power supply section. Regardless if you are fixing and troubleshooting plasma tv, vcd, lcd tv, monitor, dvd, cctv, printer, satellite receiver, xbox, audio equipment, atx power supplies, power adapter, data projector, you absolutely must have this unique effective book to demonstrate you the way to be an expert on switch mode power supplies repair and smps troubleshooting in just 7 days guaranteed.
When plugged into an ac mains, 115v or 230vac is first rectified and smoothed by a set of diodes and capacitors, which provides high voltage dc. Switchmode power supply troubleshooting safety the primary danger to you is from the input side of the supply which is directly connected to the ac line and will have large electrolytic capacitors with 320 v or greater dc when powered often, even if the supply does not work correctly and for some time after being unplugged especially if the power. I would have difficulty disconnecting the switching circuit without disconnecting the feedback. Atx pc computer power supply troubleshooting warning. Troubleshooting and repairing atx power supply by jestine yong. Constant current power supply a regulated power supply that acts to maintain its output current constant in spite of changes in load, line, temperature, etc. The shown unit is a cheap readymade chinese make smps circuit. Lowvoltage ac power supply 6 6 12rectifier assembly filter capacitor incidentally, the low voltage ac power supply is nothing more than a stepdown transformer with a centertapped secondary. This is what you obtain through the switch mode power supplies repair guide. Switch mode power supplies 271 pages, please visit. See more ideas about switched mode power supply, case histories and this or that questions.
This about smps repair pdf in this case is switching mode power supply switch mode power supply repair was post on. Due to prolonged usage and high temperaturs, the hv dc electrolytic capacitors can fail. Jun, 2019 troubleshooting and repairing atx power supply by jestine yong. Here i would like to share another article with you that talks about how i have solved a slightly. A switchedmode power supply switchingmode power supply, switchmode power supply, switched power supply, smps, or switcher is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently. The cost of replacement of power supplies for pcs in particular is so low, that just buying a new power supply may be the best course of action. Suppose you suspected a failedopen diode in this power supply circuit. Discover how the switch mode power supplies operates for the atx in pc smps troubleshooting and the power mosfet technology. These devices are incredibly reliable, but being very often left powered all the time even when their load is switched off, they still are the weak link. On the switched mode power supply i viewed in the arrl 2005 handbook for radio amatuers page 11.
In the meantime, please take note of the following tips to ensure each and. Jan 12, 20 this about smps repair pdf in this case is switching mode power supply switch mode power supply repair was post on. When the power switch is on, the input voltage is connected to the input of the. The manual is perfect as a reference guide for computer power supply repair.
Switch mode power supplies smpss are used in a range of applications as an efficient and effective source of power. Nov 01, 2007 on the switched mode power supply i viewed in the arrl 2005 handbook for radio amatuers page 11. Test the ic by removing it from the printed circuit board and installing it in a power supply that you know to be good. Fp29 power supply for ft mark v 200w radio this is power supply is a switchmode smps design. Lcd and crt monitor power supplies, lcd tvs, dvd players, and many other electronic devices that contain a switch mode. If you need a computer smps service manual, then allow me to share with you a few tips to ensure you get only the best quality manual.
Gagi9a6aag according to my kapersky software the above link in infected with a trojan. Supply pressure transducer sxdcr the sxdcr monitors the supply pressure and prevents the. Chapter 5 offers an info packed guide on troubleshooting a dvd players power supply. This short infos about smps repair in this case is ebook switch mode power supply repair guide pdf was post on. This reference manual contains useful background information on switching power. And speaking of troubleshooting guide, theres one that will come in handy for anyone wishing to learn how to repair various switch mode power supplies. Chapter 2 provides a solid overview of a dvd players power board, decoder, and loader. Its operation can be seen as having two distinct time periods which occur when the series power switch is on and off.
That is why i am aware you are likely to be delighted if you discover this web site, while there is finally a sure and guarantee method to learn the secrets of. Switch mode power supplies repair guide donwnload pdf. Troubleshooting and repairing smps switch mode power supply guide. Many power supplies have an external switch located at the rear of the unit.
Power supply troubleshooting and repair tips youtube. In the meantime, please take note of the following tips to ensure each and every troubleshooting case goes smoothly for you. They differ in the way the magnetic elements are operated. You will be aware how you can isolate troubles in smps to accelerate your repair. Mode power supply reference manual should prove useful. The same switch may be used to wake the pc from standby mode.
Whether you are an experienced power supply designer, designing your first switching power supply or responsible for a make or buy decision for power supplies, the variety of information in the switch. Plug the psu power cable into a wall socket or surge protector, and turn on the computer. A switchedmode power supply smps is an electronic circuit that converts power using switching devices that are turned on and off at high frequencies, and storage components such as inductors or capacitors to supply power when the switching device is in its nonconduction state. The power supply module is not connected properly or is faulty. A switch mode power supply regulates an output voltage with pulse width modulation pwm. Secrets of smps repair and troubleshooting switch mode power supply smps repair sometimes can be easy and sometimes are quite difficult to solve the problem. Lcd and crt monitor power supplies, lcd tvs, dvd players, and many other electronic devices that contain a.
Power supply circuit pdf switch mode power supply repair. Offline flyback regulators are mainly used for an output power ranging from 30w up. Like other power supplies, an smps transfers power from a dc or ac source often mains power to dc loads, such as a personal computer, while converting. The definitive guide to switchmode power supply designfully updated. Repairing switch mode power supplies brought to you by jestine yong. Direct link troubleshooting and repairing switch mode power supply. This doesnt apply to obsolete at pcs, where youll see the heavy power cord going to a large switch, but those systems are pretty much gone. For countries that use the 220 to 240 vac, the dc voltage that you will get is about 300vdc and for countries that use 110120vac, the dc voltage that you will get is about 150 to 160 vdc. Applications of different topologies and their pros and cons are also discussed in detail. A switched mode power supply switching mode power supply, switch mode power supply, switched power supply, smps, or switcher is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently. Jul 03, 2012 power supplies electric power controls models 8821 and 8823 switch mode power supply repair guide bravada with 4. A shorted small ceramic capacitor in the main board can cause the whole power supply to malfunction. Cisco expandable power system 2200 hardware installation.
Comprehensive colored photos 246 diagrams and pictures. Mar 12, 20 uncover battletested switch mode power supply repair strategies by downloading this allinclusive smps troubleshooting manual thats stuffed with color photos. Aug 25, 2019 a bridge rectifier can be normally seen at the beginning of any smps circuit and is introduced primarily for rectifying the mains ac to a full wave dc, which is further filtered using a filter capacitor and applied to the mosfetinductor stage for the intended flyback primary side switching operation. Smps repair guide switch mode power supply repairing tips. How switch mode power supply works smps troubleshooting. Forwardmode converter fundamentals the most elementary forwardmode converter is the buck or stepdown converter which can be seen in figure 1. I have a spare power supply with a socket in it that i use exclusively to test integrated circuits. When switch 1 mosfet 1 is on and switch 2 is off, the energy is transferred to the load rl through transformer, c2, and d1.
Troubleshooting and repairing switch mode power supply. You need to connect between pin 14 to any ground com pin to turn on the power supply. Jun 05, 2012 click here to read testimonial and buy the smps repair ebook. A switched mode power supply smps is an electronic circuit that converts power using switching devices that are turned on and off at high frequencies, and storage components such as inductors or capacitors to supply power when the switching device is in its nonconduction state. Power supplies electric power controls models 8821 and 8823 switch mode power supply repair guide bravada with 4. Switch mode power supplies repair guide smps troubleshooting. Understanding the functions of switch mode power supply. If the switching circuit is not functioning thus there will be no output voltage because the switch mode transformer is not working. Here are some negative things about those guides 1 the instructions were difficult to understand. Understanding the functions of switch mode power supply troubleshooting linear power supply is extremely straightforward as opposed to smps or switch mode power supplies. Check that it has not been accidentally been switched off. Secrets of smps repair and troubleshooting switch mode.
If n n p n s is the turns ratio of the transformer we have. For anybody still working on a desktop, look for the fan output in the central processing units cpu. Repairing switched mode power supplies smps all about. Covering the latest developments and techniques, switchmode power supply handbook, third edition is a thorough revision of the industryleading resource for power supply designers. It runs on the switching regulator to be better in its function. Describe how you could detect its presence without using an oscilloscope. Chapter 4 tells you exactly how a dvd players smps work. Troubleshooting television power supply pdf smps repair ebook. Yaesu fp29 power supply stopped working qrz forums.
Sep 16, 2018 the manual is perfect as a reference guide for computer power supply repair. The output voltage rating of a power supply operating in the constant current mode analogous to the output current rating of a supply operating in the constant voltage mode. Furthermore, the risk of a faulty repair causing expensive or fatal damage to the mainboard and peripherals including total loss of all data stored on disk. Ebook smps design pdf pdf troubleshooting and repairing switch mode power supplies can be extremely confusing thing unless you have some one that will help you through the whole process. Since you are testing on the junk motherboard first you need to create a switch to turn on the power supply. How to repair a switchmodepowersupply smps homemade. Troubleshooting linear power supply is extremely straightforward as opposed to smps or switch mode power supplies.
How to repair a switchmodepowersupply smps in this post we try to diagnose a burnt smps circuit and try to troubleshoot and repair the circuit. This article is written as per the request made by mr. This can be a problem, people generally speaking fail at repairing the switch mode power supplies ergo they dont make anything as a result. Actually, ive downloaded a couple of pdf repair guides but they werent much help.
The dc voltage that you get is measured across the two pins of the filter capacitor using a multimeter. Ac voltage gets into the primary part in linear transformer after which modified the ac in a decreased or increased ac voltage with regards to the second transformer winding. I am jestine yong and i am a specialist electronic repairer. Sun, 09 dec gmt jestine yong switch mode pdf jestine yong reserves the right to use the full force of. Notes on the troubleshooting and repair of small switchmode. Computer power supply troubleshooting atx pc power. There are several topologies commonly used to implement smps. Power supply troubleshooting and repair tips mr carlsons lab. Most power supply models have a light on back of the unit that glows when its powered on.
The power supply fault could be an open start up resistor only or could be even more than ten components burnt due to heavy lightning strike. Offline smps failure modes pwm switchers and dcdc converters. Jul 11, 2018 many power supplies have an external switch located at the rear of the unit. If the supply is still inoperative, the integrated circuit may be bad. Troubleshooting and repairing smps switch mode power.
This manual includes basic information for switching power supply, general. A switch mode power, also known as switcher, is really a power device thats used to convert the volt and current features in one form to another. Click here to read testimonial and buy the smps repair ebook. It prevents the central tire inflation system from using air from the supply tank until the brake system is fully charged or when the pressure falls below safe levels. Dont waste anymore of your precious time to search from the internet to learn the basic repair. Secrets of smps repair and troubleshooting switch mode power. Blown fuse in general conditions, blown power fuse indicates problems in internal circuits. In this ebook, you will learn all my advance troubleshooting and repairing secrets and you can become a professional in switch mode power supplies repair. New design methods required for powering small, highperformance electronic devices are presented.
Verify that both the ac ok and and ps ok power supply module leds are green. Feb 06, 2011 switched mode power supply repair guide. Offline flyback regulators are mainly used for an output power ranging from 30w up to 250w. Feb 05, 2017 power supply troubleshooting and repair tips mr carlsons lab. Chapter 3 shows you the typical components found in a dvd player switch mode power supply smps. The power supply operates under high voltage and current. Troubleshooting television power supply pdf smps repair. This process creates highfrequency noise but it provides a highefficiency rating in a small form factor.
Each basic type has its advantages and disadvantages. Fp29 power supply for ft mark v 200w radio this is power supply is a switch mode smps design. Voltage fluctuations or surges of power grid often give rise to instant increase of current, which may result in blown power fuse. The xps cannot communicate with the 3750x or 3560x switch.
The big high power components and small heat sinks are typical of smps. This application note, which is the first of a twopart series, explains the basics of different smps topologies. Reference manual bulletin 1606 switched mode power supplies catalog number. Like other power supplies, an smps transfers power from a dc or ac source often mains power to dc loads. Troubleshooting and repairing atx power supply brought to you by jestine yong i hope that you have enjoyed the short report of the easy way to understand switch mode power supply. I know its not easy to find a highquality manual for servicing and repairing switch mode power supplies or smps. They convert the line ac voltage to lowvoltage highcurrent dc.
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