The switching power supply continues to increase in popularity and is one of the fastest growing markets in the world of power conversion. Pdf this publication is a very good resource for someone beginning a career or entering education in the poert supply design field. The most common failure is the switching transistors themselves. It is nice to have a backup plan procedure when the power supply cannot be repaired with its original replacement parts. Unfortunately, smps are a bit tricky to repair and i often get asked for advice. Varistor is one of the main components in a switching power supply and it is designed to safeguard electronic item from being damaged by transient voltages which are generated by lightning. Expand the upload pdf files dropdown and select your files. Nov 20, 2017 discover how to repair smps power supply using a super crazy detailed tutorial manual for troubleshooting all sorts of smps problems. Includes power supply specifications and troubleshooting tips. If not, power supply controller will not tell power supply to power on. Considering the multiple dc voltage levels required by many electronic devices, designers need a way to.
Secrets of smps repair and troubleshooting switch mode. In addition, electric leakage of filtering capacitor results in unstable voltage output. This section contains free ebooks and guides on smps, some of the resources in this section can be viewed online and some of them can be downloaded. If not, check each wire in the power cable, through the fuseholder, and through the switch. Im currently trying to repair a switched power supply. Mar 12, 20 learn how to fix switch mode power supplies with this. Go directly to the transformer if necessary to find out why you arent getting continuity. Fortunately, its not difficult to fix pc power sup plies. Browse other questions tagged power supply repair or ask your own question.
This application note, which is the first of a twopart series, explains the basics of different smps topologies. Incorrect reassembly may result in a risk of electric shock or fire. All posts tagged atx power supply repair one zener diode found cracked and another shorted in cctv smps this 12v smps of a cctv camera was given to me by my technician friend, stating that it was reported to be dead. When the power supply was switched on, measurements were taken. Dont throw away your damaged power supply when you can send it to acs for a free evaluation and repair quote.
In most switching supplies, the 110 volt ac input is first rectified by two diodes and filtered by a pair of capacitors. Notes on the troubleshooting and repair of small switchmode. Comments on smps capacitor discharging and testing with series. If in doubt about your ability, let an experienced repair tech do it or just replace the power supply. Damaged components can be found out by checking relevant. Never use the power supply for a load requiring higher current than the designed value. Recover data from a corrupted or damaged pdf document. Power supply failures can be a nightmare for a variety of reasons.
The diodes in the bridge rectifier appears to be the normal 1n4007 diodes which are capable of handling not more than 1 amp current, therefore if this 1 amp value exceeds the diodes can get. Check out the link below for all the info you need. How to repair a dead computer power supply psu fault. The repair of switch mode power supplies smps is economically a good investment for electronics repair shops and for hobbyists. Smps repair guide switch mode power supply repairing tips.
This project deals with the transmission of the audio signal wirelessly and amplification of the received signal using vtf108 bluetooth module and audio amplifier ic ta8210ah. Right now, were going to take a look at 3 of the most common mistakes that newbie technicians make when repairing switch mode power supplies or smps. Need help repairing adjustable dc power supply stuck on 48v. A dummy load can be made from a couple lamps that you can buy at any auto parts store and an extension cable from radio shack. This manual was originated from switching power supply user manual. Power supply repair, schematic diagrams 0 use of audio amplifiers is increasing day by day. 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. Discover an extensive array of switch mode power supply repair strategies by downloading a meticulously put together smps power supply repair ebook that has more than 200 pages worth of step by step content. 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. Using a laptop or computer power supply repair can be extremely difficult especially for novice experts. 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. Acopian power supply repair acopian power supplies.
Power supply troubleshooting pc repair and maintenance. Repairing switched mode power supplies smps all about. It is often helpful to trace the circuit by hand if a service manual is not available. Power supply failures i have found that there are only a small handful of components that fail in switching regulator power supplies. Switching power supplies, pioneer magnetics, switch mode. With the supply unplugged, turn the power switch on and use the ohmmeter to measure across the two power prongs of the power plug. Smps repair guide stepbystep and so easy to follow. Switching power supply repair guide repairing the switching power supply can be processed in two steps.
And i check inside, the ac input bridge rectifier in4007 1diode got damaged. In case of power off, users can carry out maintenance by visual check, smelling, asking and measuring. There are several topologies commonly used to implement smps. It must be more than 2 volts before switch is pressed and must drop immediately to less than 0. We recently received a switching power supply that failed in the field so we took the opportunity to do some troubleshooting and discuss the process here on. Chances are that if you used any computer for more than a few years without swapping out its power. As a favour to my customer, i took up this repair job. The oems support website should have the service andor a comprehensive users manual available for download in pdf format.
Most of them are flyback, regulated, smps but not all. The transistors shortcircuit, causing massive amounts of current to be drawn across the transformer and blowing the fuse. From the image it appears that the entire design is based on a mosfet, inductor switching topology wherein the mosfet becomes the main switching element in the circuit. A case study in psu repair dont try this at home tom. Open shell of the power supply to check whether the power fuse has been blown. Mode power supply reference manual should prove useful. This circuit is used to convert the dc supply into high frequency, high current ac, which by various means. And speaking of troubleshooting guide, theres one that will come in handy for anyone wishing to learn how to repair various switch mode power. Buy supernight 12v 30a dc power supply driver, 360w universal regulated switching converter ac 110v220v transformer adapter for 3d printer, cctv, radio, computer project, industrial automation, led strip. Switch mode power supplies smps are now standard for the majority of our home. Of course, like any good troubleshooters and according to the pcb troubleshooting flowchart we gave the power supply a good visual inspection.
Since 1987, power clinic has provided reliable and responsive power supply repair capabilities whether linear, switch mode, single phase, three phase, ups, high voltage, acdc, dcdc, programmable for every topology and application imaginable. How to repair a switchmodepowersupply smps homemade. Troubleshooting switch mode power supplies on giangrandi. How to repair a computer power supply or other switching. It says 517 power supply error and i have to hit f1 to boot. You realize, this smps power source restoration manual is a important guide i use again and again. They offer the designer several important advantages over linear seriespass regulators. The diodes in the bridge rectifier appears to be the normal 1n4007 diodes which are capable of handling not more than 1 amp current, therefore if this 1 amp value exceeds the diodes can get ripped through and damaged. With over 60 years of excellent service, pioneer magnetics, inc.
Free smps books download ebooks online textbooks tutorials. Switching power supply repair discover 3 must avoid. Note that a quality power supply has a an operation efficiency of about 80%, meaning that 20% of the electrical power supplied to the computer, will be lost inside of power supply turning mostly into heat or be lost as reactive energy if the power supply does not have active pfc power factor correction. My new smps modification repair ebook jestine yong. Repairing switching power supply modern power supplies are known as switching regulator power supplies. This is great as it was already on my list of things to do to understand switching power supplies better as the old school transformer. Applications of different topologies and their pros and cons are also discussed in detail. The primary has one driven by the power switch mosfet, the other is for both powering the chip after it. Tips for repairing smps switch mode power supply discover some awesome tips on how to repair switch mode power supply smps. See more ideas about switched mode power supply, case histories and this or that questions. Very often when i attempt to repair electronic devices, either mine or from friends, i find out the problem is with the power supply which these days is most often a switched mode power supply smps.
Place the power supply on a flat surface with sufficient clearance and dry. Switch mode power supplies repair guide donwnload pdf. Whatever you prefer to call it power supply, rectifier, power system, power module, power brick we make millions of different kinds that can be used in thousands of different applications including electronic equipment, manufacturing, machinery, process control, factory automation, astrophysics, chemical processing. An introduction to switch mode power supplies sep 27, 2007. If the power supply makes no attempt to switch, verify that the semiconductors are installed properly and are not damaged. Switching power supply technical manual adm instrument. Good replacement powersupplies on amazon how to spot a bad power supply and how to fix it. Computer power supply repair dead bad capacitor no flashing. This guide will present all of the switch mode power supplies troubleshooting strategies in addition to easy methods to begin power supply repair job from the comfort of your house utilizing proven tactics which are effective over the entire planet. This manual includes basic information for switching power supply, general.
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