How To Repair A Dead AC-DC Power Supply Model: STD-1202
A dead power supply was brought to me by my Pastor. This power supply is used to charge the transmitters and receivers that are used for translation in my church. When I powered up the power supply, the light did not come on indicating a problem in the device.
The output is 12 volts and the amp rate is 5A. The reason for high amp rate because this power supply charges up to about 40 devices at the same time.
Every device has two rechargeable batteries so you can imagine the output load on this power supply.
Take this power supply apart was so easy thanks to the only two screws on the bottom of it. Once these were off, the internal board was exposed and ready to be worked on.
As you can see, it looks clean and it seems like nothing was wrong with it. Once it was flipped to the other side, it was different story.
The only thing I could see on this board was the cold soldering join found on the dark SMD resister. Sorry to tell, you that after re soldering that resistor, the charger was not even close to being fixed. The resister was in good working condition.
I have seen this happen very often in the power supply repair. The output cable sometimes gets shorted out causing the power supply to be dead. So, the next step was to disconnect the output cable and you can see in the previous photo, it was out.
The light came one indicating a shorted output cable. Lucky for me, I have found a replacement in my shop.
This is the new output cable that was re soldered back to the power supply. Once that was done, I powered up the power supply and checked for voltage ready, it was working fine.
Mission Accomplished.
This article was prepared for you by Waleed Rishmawi, one of our ‘Master Authors’ and currently working in the Bethlehem area of Palestine repairing electrical and electronic equipment.
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Note: You can check his previous repair articles in the link below:
https://www.electronicsrepairfaq.com/how-to-get-rid-of-hissing-sound-in-welding-inverter
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Jestine Yong works as an Electronics Repair Lecturer in Kuala Lumpur Malaysia and his training website is http://www.NoahtechElectronicsTraining.com. You can check out his repair blog at http://www.JestineYong.com
14 comments on “How To Repair A Dead AC-DC Power Supply Model: STD-1202”
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that was fabulous! Bt i need also sme help here , may plasma tv has totally refused to open up the screen the blue lining still remains dividing the screen , i have tried changing countless vertical ics bt all in vein, this has taken me a month now ,plz any help or advice
Very useful information!
Since the demand is high for this PSU, I would suggest replacing the jack and using a bit thicker cable. Good job, though and your Pastor is lucky to have you, too.
Yes, indeed a common failure. That is why it is best to always start with the adapter before opening any not working laptop or other device too.
Waleed, it´s normally possible and easy to repair the cable. Didn´t you tried it?
good job sir
plz keep it up
Good job, Waleed. It is always good to check the simple things first. I forget to do that once in a while myself.
Oh! I have to check whether the output cable was short-circuited or not before go further to troubleshoot the pcb. Thanks!
it is a very clear report from waheed.thanks very much.keep it up sir.
Excellent and interesting job ,thanks Walleed and I am awaiting for the next article -keep up the good job.
Good job, Mr,Waleed
Thanks For Details.
Good job, all the very best
Good job! waleed
Wow !!!
U’re luckier my master but even skills & knowledge actually god is first right ?