I’d stopped repairing ATX power supply several years back because of the new one cost very cheap. It’s not worth to correct it since the spare parts sometimes were much higher priced than getting a new power supply. Searching for ATX power supply spare parts wasn’t easy as most of them you can’t even see them on the internet. Not only that, many complicated and different designed by power supply manufacturers had eaten up our precious troubleshooting time too as a result of we truly need time to know the way all these different designed power supply work.
Some of the power supply designs were utilising the PWM IC (UC3842) and power FET, some utilize the double transistors while some use just a single power IC in the principal side. Because of the manufacturers wants the style to be converted to compact size, many secondary as well as primary power supply circuit were build into a modular board (smaller board). This made troubleshooting even harder because often the meter’s probe can’t reach to the testing point.
The real reason I’d stopped repairing ATX power supply was the profit margin. In the event that you charge to high the customers rather buy a new unit with twelve months warranty given. In the event that you charge too low, you might result in the losing side due to the P2001 power station components replaced, electricity and etc. In the event that you charge reasonable, the profit margin gained can’t even cover your own time used on troubleshooting it. I’m here not to discourage you to avoid repairing ATX power supply, however when you have the time, have contacts getting cheap power supply components, easily accessible many power supply schematic diagrams and etc you might go ahead to fix it.
Okay back again to the article, certainly one of my customers had asked me to fix his ATX power supply. I told him to get a new one (since it absolutely was very cheap) but he explained he couldn’t find one which suits his customer’s CPU. He wanted a power that is either same size or smaller then your original one with same or older specification but all he could find was a typical size power supply!
As a favors to my customer, I’d do my best to help him to fix the ATX power supply. When the energy supply was switch on, measurements were taken. The results were over voltage. The 12 volts line shot around 13 + volt and the 5 volts line became 5.6 volts. Following the casing was removed, I discovered the interior was very dirty and I used a vacuum cleaner and a comb to wash off the dirt. Then I saw four filter electrolytic capacitors had bulged at the top casing.
You may already know, we as electronic repairers can’t just see things at only 1 side; we have to see another sides too. What After all was, try to see if there are any suspicious components that contributed to the failure of the energy supply such as broken components, dry joints, loose connection, decay glue and etc before start checking the suspected area.
What I saw was at the principal side there have been some components covered with decayed glue as noticed in the picture. I need certainly to carefully take it off by scrapping off the layers of the decayed glue while preserving the outer layers of the components. Once it absolutely was done, I clean it with the Thinner solution. Decayed glue may cause serious or intermittent problem in electronic equipment because it can be conductive.
In the event that you repair any ATX power supply, make sure you check the fan too because some power supply failure was because of heat the result of a faulty fan. The purpose of the fan is always to suck out all the heat generated by the components inside the energy supply. For the fan to run smooth, you can service it with a Philips oil base spray as shown in the photo.
When the four electrolytic capacitors were replaced and the decayed glue removed, I then need certainly to plug it into a junk motherboard as well as a hard disk drive to try the performance of the ATX power supply and measure all its output voltages. It seems like the output voltages were back again to normal. Once everything is okay I then test drive it in a working CPU to test for the display.
The reason why I test drive it with a junk motherboard first as a way not to cause my good motherboard to go south in case if the output voltages continues to be very high. Better safe than regret later. In addition you can’t test a power without load otherwise it may switched on for a while and then shut down. If you may not have a junk motherboard you can always at least connect a drive and a line jumper to its connector to turn on the ATX power supply.