How to solve this meanwell power supply. - Page 1
Forum section: electronics / repair

author: SDBFG
author_rank: Contributor
timestamp: April 24, 2018, 05:43:12 am
content: hello siri have meanwell 24V 5V suply does to earthing by conductor body it get short.please help me.

author: Zero999
author_rank: Super Contributor
timestamp: April 24, 2018, 09:36:27 am
content: Quote from: SDBFG on April 24, 2018, 05:43:12 amSorry Google translate is failing here. That means absolutely nothing.Can you post a schematic?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 24, 2018, 10:59:16 am
content: did he say the green earth connector is shorting something@sdbfg could you explain better

author: SDBFG
author_rank: Contributor
timestamp: April 24, 2018, 11:28:05 am
content: when i connect the supply to main it fuse break and mcb of power fall down..

author: Messtechniker
author_rank: Frequent Contributor
timestamp: April 24, 2018, 11:53:28 am
content: First check: is anything conductive trapped between pcb and casing?

author: drussell
author_rank: Super Contributor
timestamp: April 24, 2018, 12:01:36 pm
content: Shorted Y-class EMI filter cap, perhaps? They are supposed to fail open, but who knows... ??

author: SDBFG
author_rank: Contributor
timestamp: April 24, 2018, 01:29:37 pm
content: Quotehello siryes it get shorted by pcb and casing?now please tell how to know more about it.Shorted Y-class EMI filter cap, perhaps?and yes it was spark from capacitor.how to repair it?

author: german77
author_rank: Regular Contributor
timestamp: April 24, 2018, 02:54:56 pm
content: I understand that you don't speak English but please be more descriptive that way we could figure out what are you trying to say, from the very bad translationsYou should find the source of the problem if you do it step by step.You will need a multimeter, a soldering iron, flux, solder wire and a solder wick.First unplug everything from the PSU.Then look for visual damage, for example A component that it's blown, a bulky capacitor, the PCB shows signs of heat discoloration, two leads touching in mid air, or more probably the black electrolytic capacitor from the far right looks like it has black junk on the bottom and the one where you saw a spark.Then check each fuse, capacitor on the pcb, A fuse must show short and a capacitor must have a very high resistance.Remove and test each component that failed the visual or the conductivity test. If the component doesn't work replace it with a new one, if the component work's as it should, follow the pcb traces and find the faulty one.After every faulty component has been replaced, check the resistance of the AC terminals it should be more than 100k, then check the resistance of the power rails it should be around 300 ohms. If one of these show something different the problem is not solved, you should check diodes, transistors and ic components, and on the very last the resistors.Then after you are sure that everything works as it should, connect the PSU to the mains. If it works then connect the load. If the fuse blows again, you have a short on your load.There are plenty of videos were they show you how to find, test components and replace them, specially for PSU.If you don't have any idea of what you are doing, or think it's to much work. I would recommend to just buy a new one.