I’d stopped repairing ATX power many years back as a result of new one cost very cheap. It’s not worth to fix it because the spare parts sometimes were much more expensive than finding a new power supply. Searching for ATX power spare parts was not easy as many you can’t even locate them on the internet. Not only that, many complicated and different created by power manufacturers had eaten up our precious troubleshooting time too due to we want time and energy to understand how every one of these different designed power work.
A number of the power designs were utilizing the PWM IC (UC3842) and power FET, some utilize the double transistors though some use only a single power IC in the principal side. Due to the manufacturers wants the design to be converted to compact size, many secondary as well as primary power circuit were build in to a modular board (smaller board). This made troubleshooting even more challenging because often times the meter’s probe can’t reach to the testing point.
The true reason why I’d stopped repairing ATX power was the profit margin. If you charge to high the customers rather obtain a new unit with one year warranty given. If you charge too low, you might end up in the losing side due to the components replaced, electricity and etc. CN505 power station If you charge reasonable, the profit margin gained can’t even cover your time spent on troubleshooting it. I’m here never to discourage you to stop repairing ATX power, however when you yourself have enough time, have contacts getting cheap power components, easy to access many power schematic diagrams and etc then you might go ahead to repair it.
Okay back to this article, one of my customers had asked me to repair his ATX power supply. I told him to obtain a new one (since it had been very cheap) but he said he couldn’t find one that suits his customer’s CPU. He wanted a power that’s either same size or smaller then your original one with same or older specification but all he could find was a typical size power!
As a favors to my customer, I’d do my best to help him to repair the ATX power supply. When the ability supply was turn 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. After the casing was removed, I came across the within was very dirty and I used a hoover and a comb to wash off the dirt. Then I saw four filter electrolytic capacitors had bulged towards the top casing.
Everbody knows, we as electronic repairers can’t just see things at just one side; we’ve to see another sides too. What I am talking about was, try to see if you can find any suspicious components that contributed to the failure of the ability supply such as for instance 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 observed in the picture. I have to carefully take it off by scrapping off the layers of the decayed glue while preserving the outer layers of the components. Once it had been done, I clean it with the Thinner solution. Decayed glue may cause serious or intermittent problem in electronic equipment because it could be conductive.
If you repair any ATX power, be sure you check the fan too because some power failure was as a result of heat caused by a faulty fan. The purpose of the fan is always to suck out all heat generated by the components inside the ability supply. To ensure that the fan to run smooth, you are able to service it using a Philips oil base spray as shown in the photo.
Once the four electrolytic capacitors were replaced and the decayed glue removed, I then have to plug it in to a junk motherboard along with a hard disk to try the performance of the ATX power and measure each of its output voltages. It looks like the output voltages were back to normal. Once everything is okay I then test drive it in an operating CPU to check on for the display.
The reason why I test drive it with a junk motherboard first as a way never to cause my good motherboard to go bad in the event if the output voltages remains very high. Better safe than regret later. By the way you can’t test a power without load otherwise it might switched on for a time and then shut down. If you do not have a junk motherboard you are able to always at the very least connect a hard disk drive and a cable jumper to its connector to turn on the ATX power supply.