The switching power supply continues to increase in popularity and is one of the fastest growing markets in the world of power conversion. In this work, factors responsible for this erratic power supply were discussed. Electricity generation and the present challenges in the. An external power supply, ac adapter or power brick, is a power supply located in the loads ac power cord that plugs into a wall outlet. Oct 11, 2015 the most common and most expensive problem is that the batteries need to be replaced quite regularly. Oct 09, 2017 in this video i show how to repair an atx computer power supply and what are the most common failures. These are popular in consumer electronics because of their safety. What are common problems faced with uninterruptible power. The primary function of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. 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. Hello everyone, happy new year and welcome to the order. It gives 12 volts, 9 volts and 5 volts regulated dc. However, brand name manufacturers, especially older dells, often used proprietary power supplies and made up their own color coding, so i wouldnt throw out a power supply that supplies 5v where you think it should supply 3. 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.
The seven types of power problems schneider electric. Its easily identified by a warning sticker on the case that reads caution. When you suspect that the power supply is causing a problem, swap the power supply, make the customer happy, and be on your way. In this daily drill down, rodrigo zamora gives you a troubleshooting process to isolate these powerrelated problems. A faulty pc power supply belies many intermittent computer problems. They offer the designer several important advantages over linear seriespass regulators. Failure to do so may result in damage to your power supply or system, and may cause serious injury or death.
Pdf power supply problems an overview of underand over. Experience can help a tech diagnose problems caused by a faulty power supply that. Erratic power supply can also be equated to negative power in situations where the flipflop nature of the supply causes. The color of the wire identi fies the voltage and its use table 1.
Typically, a stalled cooling fan is a predictor of a power supply failure due to subsequent overheated components. Understanding and troubleshooting the pc power supply. 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. An under powered power supply can also limit system expansion. The electrical device might be an electric motor, a transformer, a.
The color scheme used for each voltage in the 24 pin connector holds for the other atx standard power supply connectors. The lower the ripple factor of a power supply, the better it is. It should not be inferred that all power supplies must conform exactly to the content of this document, though there are key parameters that define mechanical fit across a common set of. A power supply is an electrical device that supplies electric power to an electrical load. Power problems are not usually difficult to detect or troubleshoot. Jul 19, 2001 a bad power supply can be the root of many pc problems. Pdf this publication is a very good resource for someone beginning a career or entering education in the poert supply design field. If none of the devices is the cause of the problem, replace the power supply. Test the internal power supply if the bist is not available on the psu. Power quality issues, impacts, and mitigation for industrial. This document provides design suggestions for various power supply form factors.
A bad or poor power supply can cause numerous problems for a pc. A power surge takes place when the voltage is 110% or more above normal. With the dead supply turned on, it was getting 340v dc to the board. Within this standard, recommended limits are provided for individual harmonics and total distortion. The most common and most expensive problem is that the batteries need to be replaced quite regularly. Suddenly, today, while sending ft8 at about 30 watts, the power supply protection alarm led and buzzer came on and the icom lost its power. These advantages include significant advancements in the areas of size and weight reduction, improved efficiency, and. Jan 01, 2016 hello everyone, happy new year and welcome to the order. These problems cause voltage and current instability which can have a significant impact on equipment operation and power usage. The most common cause is heavy electrical equipment being turned off. Suppose you suspected a failedopen diode in this power supply circuit. Unplug any internal power cables from the psu to the motherboard and internal devices. Pdf ever since the loadshedding events of early 2008 as a result of severe capacity constraints experienced at the time, greater emphasis has been. Here are some of the most common power problems and their likely effect on sensitive equipment.
Nigeria has been battling with the problem of power generation, that would meet the growing demand both on the small and large scale. Most of these tips can apply to any switch mode power supply smps. Scott mueller shows you how to test, remove, and install a power supply. Make sure the cord is firmly seated in the wall socket and in the power supply socket. Power supply repair ultraportable plc reference design for industrial automation maxims new goio plc reference design drives intelligence to the digital factory edge, enabling active. How to troubleshoot a no power issue on your dell desktop. I have used it with my icom 7300 just about every day with no problems. This white paper will describe the most common types of power disturbances, what can cause them, what they can do to your critical equipment, and how to safeguard your equipment, using the ieee standards for describing power quality problems. Power supply troubleshooting pc repair and maintenance. Imagine that your pc shuts down without any warning and it doesnt want to turn. This is why experienced pc technicians often look first at the psu when diagnosing pc hardware issues. Problems of electricity in nigeria top 10 causes and solutions the economy of any country thrives directly or indirectly on the availability of electricity in the country. Power supply problems an overview of under and overvoltage events abstract ever since the loadshedding events of early 2008 as a result of severe.
In this daily drill down, rodrigo zamora gives you a troubleshooting process to isolate these power related problems. Reliability considerations for power supplies cui inc. Includes power supply specifications and troubleshooting tips. Do not open the power supply case or attempt to repair the power supply. Since 2005, the whole sector was privatized, and now its the sole responsibility for them. The factors include governments inconsistent and misguided power reform policies.
Describe how you could detect its presence without using an oscilloscope. Power supply designers are using flexible supply monitoring, sequencing, and adjustment circuits to manage their systems. It heats and cools each time it is used and receives the first inrush of ac current when the pc is switched on. The power supply acts as a stepdown transformer converting high voltage ac into 5, 12, and 3. Apr 24, 2001 power supply problems often masquerade as device or software problems. As a result, power supplies are sometimes referred to as electric power converters. But it is not just the supplys own dissipation which causes the supply to operate at higher temperatures. If the led is still off, the power supply is at fault. Common issues with power supply may 6th, 2016 filed under power quality common problems with power supplies explained. Jul 11, 2018 when a pc suddenly goes on the fritz for no apparent reason, checking the pc power supply first may save a lot of time troubleshooting the system. There is also a common problem with describing power problems in a standard way. Here are some of the most common power supply problems and their likely effect on sensitive equipment. Today i will tech you how troubleshoot a pc power supply.
All electrical devices are prone to failure when exposed to one or more power quality problems. Tutorial how to troubleshoot a pc power supply psu. 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. To check the power supply, swap it with one from a similar working computer and see where the fault goes. 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. Calculate the unloaded dc output voltage for this supply assume 0. Following is a simple flowchart to help you zero in on common power supply related problems. Tips on repairing smps power supplies without published schematics. Some power supply problems that may cause boot, lockup, and stability problems include.
A dc power supply unit commonly called a psu deriving power from. This paper therefore presents a brief history of the attempts and efforts to supply power to the nation. The pc power supply is probably the most failureprone item in a personal computer. If replacing the power supply does not solve the problem, replace the motherboard. 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. A power supply a delivers 10 v dc with a ripple of 0. Youll get more life out of the batteries if they are kept cool. Why do power supplies fail, and what can be done about it. Check lm723c supply at d1 or d2 cathode on the trace side of the pcb for 25 to 29 volts load dependant output. Top 15 common electrical problems and solutions panasonic. Most of the power that the supply provides to the electronics eventually ends up as dissipated heat within. Press the bist b uilt i n s elf t est button on the back of the psu and check to see if the led lights up for 3 seconds. Do not overlook the most obvious power supply symptom. If no audible tone is heard determine if there is a proper input voltage at the power supply and determine is you have a proper ground to the chassis of the vehicle.
In this video i show how to repair an atx computer power supply and what are the most common failures. Poor power supply background until the reforms in power sector of nigeria in 2005, the transmission of the energy into houses was the sole problem of the nigerian federal government. It is rarely recommended that an inexperienced user open a power supply to make repairs because of the dangerous high voltages present. 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.
Power supply troubleshooting and repair tips youtube. For any problems you suspect to be the fault of the power supply, use the documentation that came with your computer. A simple circuit of regulated power supply with battery backup has been designed which can be used as a work bench power supply. Secrets of smps repair and troubleshooting the fast way. From an electric utility perspective, a fault on the transmission system can produce a sag to electricity users downstream of that location, and depending on the system topology. Troubleshooting the power supply basically means isolating the supply as the cause of problems within a system and, if necessary, replacing it. Of switch mode power supply troubleshooting linear power supply was quite easy as compare to switch mode power supplies smps.
A work bench power supply is a dc power supply unit which can provide different regulated dc voltages which is used for the purpose of testing or trouble shooting. Computer power supply troubleshooting atx pc power. A bad power supply can cause lockups, reboots, and generate excessive heat, not to mention shortening the life span of other components. Even when unplugged, power supplies can retain dangerous voltage. Secrets of smps repair and troubleshooting switch mode.
Notes on the troubleshooting and repair of small switchmode. Power supply problems often masquerade as device or software problems. Repairing samsung la40r81bd 40in lcd tv power supply. This guide will help you resolve a common problem with samsung lcd tvs. Nov 01, 2000 a bad or poor power supply can cause numerous problems for a pc. 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 you have ever removed the case from your personal computer to add an adapter card or memory, you can change a power supply. Prior to the loadshedding events, customers were fairly used to power interruptions which were primarily caused by lightning or cable theft events. Overloaded power suppliesloads that exceed either the maximum output of the supply or of a particular. Problems associated with power supplies power supply voltage uncertainty.
Alot of power supply failures are actually simple problems that are easy to fix. This article outlines how to diagnose a faulty supply by testing its voltage outputs, as well as how to replace the defective unit. The power supplies are primarily intended for use with desktop system designs. Many power problems originate in the commercial power grid, which, with its thousands of miles of transmission lines, is subject to weather conditions such as hurricanes, lightning storms, snow, ice, and flooding along with equipment failure, traffic accidents and major. I have a pyramid ps36kx power supply that i bought at a hamfest about 7 months ago. Under these conditions, computer systems and other high tech. Suppose a power supply is energized by an ac source of 119 v rms. Computer power supply troubleshooting atx pc power supply. They have a separate power supply for the lm723c chip, with its own filter capacitor, c1, rectifier diodes, d1 and d2, and a transient voltage suppression diode, cr6, pk6e39a3. Symptoms include tv taking extended time to power up, power cycling onoffon, failure to power up and other similar issues. A bad power supply can be the root of many pc problems. How to repair a computer power supply or other switching. Many power problems originate in the commercial power grid, which, with its.
Here i would like to share another article with you that talks about how i have solved a slightly higher output voltages in an atx power supply. Power quality is a set of electrical boundaries that allows a piece of equipment to function in its intended manner without significant loss of performance or life expectancy. Make sure the motherboard and disk drive power connectors are firmly seated and making good contact. There are a number of problems which may occur with the incoming power supply to a site. Experience can help a tech diagnose problems caused by a faulty power supply that would normally be overlooked by a novice. Disconnect the power cord and wait at least 15 seconds before plugging it back in.
1148 317 1622 675 829 996 1243 565 1404 114 1587 1373 458 1078 983 698 308 1118 1540 786 1240 1052 786 1152 681 1130 406 1548 889 1082 1466 888 672 938 954 874 1266 1019 1201 180 6 883 730 708