Don't Miss
ATX SMPS Test
By Jestine Yong on September 5, 2007
ATX SMPS Test is very easy. Just use a scrap motherboard and connect the power supply onto it and place a wire across the two pins shown in the picture below in order to turn the ATX power supply “On”. If possible place two more harddisk to act as load just incase the single motherboard load not enough to switch it on. The symptom could be the fan rotate for a while and then totally stop!
Be cautious that not all ATX power supply support all kinds of motherboard. Some power supply just need back its own motherboard or system in order to function properly. Hope after reading this tips you should not have any more problem for ATX SMPS Test.
Likes
(8)Dislikes
(0)
(8)Dislikes(0)
370 Comments
Leave a Reply
grage
December 16, 2010 at 6:53 am
Hi JESTINE
Two days ago my system turned off abnormally. I tried general troubleshooting and power on the system. But each time I put heavy load like high graphics game, video etc, it turned off abnormally. Finally I checked the DC output of my SMPS reduced to 10.2v and 4.4v. Could you suggest a solution to it?
if it's a capacitor, can I test it with a multimeter & how?
thnx
admin
December 16, 2010 at 10:57 am
HI Grage,
It seems like the filter capacitor problem (bulged capacitors) and it need to be tested with an ESR meter. If you do not have this meter you can directly replace the caps and retest.
Jestine
kanth
December 21, 2010 at 9:31 am
Hi Sir,
This Q&A blog is really of great use.
This is regarding a problem with my ATX SMPS used for a desktop computer. As soon as the main 220V power is switched on, the PC switches ON automatically for about 3-4seconds and then powers OFF. This happens even before the Power button on the PC/Desktop is turned ON. I doubt if this could be a SMPS problem. Could you please help me understand what could have gone wrong in the SMPS?
By the way, when the desktop power button is truned ON, the system works normally. The problem is only at the initial point of switching ON the 220V supply. As long as the SMPS is left connected to 220V supply, there are no problems with turning ON and OFF the PC. The problem is only when the 220V supply is truned OFF and switched ON.
Please help.
grage
December 22, 2010 at 3:18 pm
Thnx Jestine
I was out of station for past 4 days. I replaced the filter caps but the result is same 10.2v and 4.4v. Should I check anything else?
admin
December 23, 2010 at 7:34 am
HI Grage,
Then i suggest that you check all components in the primary side especially the capacitors. Make sure you test the power supply connected to a mainboard
Jestine
admin
December 23, 2010 at 10:57 am
Hi Kanth,
It can be the problem of motherboard or the smps. Something shorted in either board could cause such problem. I suggest that you use another ATX smps to confirm it first so that you will not be in the guessing game. Troubleshooting on the wrong set could waste your time
Jestine
grage
December 23, 2010 at 12:46 pm
OK, I'll check them in free time.
thnx again
Kanth
December 24, 2010 at 1:56 am
Hi Sir,
Thanks a lot for responding. Acutally due to other major issues, I replaced the motherboard with a new one. But I am using the same old ATX SMPS. I sitll have the same problem with the SMPS. As soon as the main 220V power is switched on, the PC switches ON automatically for about 3-4seconds and then powers OFF. This happens even before the Power button on the PC/Desktop is turned ON. Could you please help me identify the troublesome part in the SMPS?
admin
December 24, 2010 at 2:51 am
HI Kanth,
In that case, you may need to open up the power supply and trace the green wire to see where it goes. It should land on a transistor and perhaps this transistor is leaky or the circuit have problem.
Jestine
Kanth
January 1, 2011 at 7:10 am
Hi Sir,
I opened up the SMPS and found only one transistor(3pin thing) on all the o/p side. I de-soldered it and found it to be TL431 (a programmable voltage reference). Did I land on the correct one?
I am not sure how to test this one though.
I will try to get a replacement for the TL431 and see if it fixes the issue. 🙂
admin
January 1, 2011 at 8:14 am
HI Kanth,
Yes the best way is to direct replace and retest the power supply. Remember to check on the corresponding components too.
Jestine
Edel Fernandez
January 5, 2011 at 1:43 am
Hi Jestine,
Good Day!
I have Hec Winpower 550w computer power supply. No bulging capacitor inside and I have found the fuse blown. I manage to replaced the fuse with same value but when I turn on my computer the fuse keeps blowing and even shorting the green and black wire.
What would be the best way to find other shorted components inside my PSU, I think something like varistors or diode maybe?
Thank you in advance Jestine!
admin
January 5, 2011 at 8:37 am
HI Edel,
Fuse blown can be cause by shorted bridge rectifier, varistor, power ic/ transistor and even shorted power transformer. Sometime a bad filter cap in the primary side also could cause the fuse to blow.
Jestine
Arun biradar
January 7, 2011 at 11:07 am
Hi, tis is realy helpful. Thanks
KAILAS KUMAR GAMI
January 8, 2011 at 7:49 am
I have ATX-7P4-3.there is problem in inverter circuit.how i can locate the fault.
admin
January 10, 2011 at 9:54 am
Hi Kailas,
What is the problem with the inverter. Is there supply voltage to the inverter ic?
Jestine
Emmanuel Limonga
January 26, 2011 at 10:43 am
i would like to know how to test a transistor using a multimeter
admin
January 27, 2011 at 9:03 am
HI Emmanuel,
All my transistor testing method i have compiled it into an ebook at http://www.TestingElectronicComponents.com
Jestine
sudip
January 28, 2011 at 10:00 am
i want to learn through net but its not possible to purchase everything in the market.so if anybody will be help about laptop repairing video i will be grateful to him.
admin
January 29, 2011 at 11:08 pm
Hi Sudip,
I suggest that you check out the laptop repair videos website at the right side of this blog.
Jestine
Arun
February 3, 2011 at 10:30 am
Is there any problem occurs in the SMPS when starting it alone by connecting pin 13 and 14 for a longer time???
admin
February 3, 2011 at 9:43 pm
HI Arun,
Some may not start. The best is to connect a load and start it.
Jestine
manish
February 11, 2011 at 7:35 pm
smps ka fuse hi kyon bar -2 fuse hota h.
admin
February 11, 2011 at 10:38 pm
Hi Manish,
Sorry i do not understand your meaning-could you elaborate?
Jestine
shrikanth
February 14, 2011 at 3:24 am
i am undestanding your good suggestion
narendra
March 3, 2011 at 11:18 am
how to repair s.m.p.s
admin
March 3, 2011 at 10:44 pm
HI Narendra,
Try check this website http://www.powersupplyrepairguide.com
Jestine
Hareesh Shetty
March 5, 2011 at 12:20 pm
i have ATX SMPS 450W in system everything working fine expect [blank] display on monitor.
If i use new SMPS system working fine with display.
can u help me out what could be the problem in SMPS.
admin
March 5, 2011 at 11:08 pm
Hi Hareesh,
YOu may need to check the power good line. A missing or bad power good line will cause no display symptom. It can be bad caps, ic and etc.
Jestine
Hareesh Shetty
March 6, 2011 at 2:16 am
Tankz Jestine. i will go through ur advice.
angela
March 12, 2011 at 10:44 pm
hi, this is angela from HongKong Kineagle Enterprise Ltd, we are smps ,psu manufacture in china, should u have any interest in our products, pls contact me directly, tks
Msn ID: kineagle.sale2@hotmail.com
Skype ID: kineagle.sale2
Website: www.kineagle.com
Email: angela@kineagle.com
pritam
March 16, 2011 at 4:21 am
Dear sir
i have a iball 400w smps,last night there were some burning smell ,i opened up my smps i found one ceramic pf blown up , still i can operate my computer every thing looks fine but the body of the cabinet gives shock, i checked earthing is ok.smps is working with blown ceramic pf near capacitor, what should i do, please help.
admin
March 16, 2011 at 11:15 am
HI Pritam,
Try replace the cap and make sure the earth from the wall socket is good because a bad connection especially the earth wire could cause slight shock in the casing.
Jestine
Pritam
March 21, 2011 at 8:51 am
DEAR SIR
i agree with u but cou ld u please tell me the value of the capacitor , can i find the cap from scrap smps. My earthing is all right on wall socket still body gives heavy shock.
admin
March 22, 2011 at 9:12 am
HI Pritam,
Sorry i do not know the value of the capacitor because there are so many power supply design out there. Yes you can salvage from a junk smps to replace it.
Jestine
sohail
March 25, 2011 at 11:49 am
very nice to see this
Ravi Kumar
March 26, 2011 at 3:04 pm
sir
i am pursuing chip level repairing in computer hardware.My first items SMPS. please suggest me how will start components checking, tracing, voltage checking etc.
admin
March 26, 2011 at 10:55 pm
HI Ravi,
I suggest that you get this ebook first http://www.testingelectroniccomponents.com . Once you are good in testing electronic components you can get the power supply repair ebook at http://www.PowerSupplyRepairGuide.com
Jestine
sanjan singh
March 30, 2011 at 8:54 am
in smps display problem
admin
March 31, 2011 at 6:17 am
HI Sanjay,
Could you elaborate the problem?
Jestine
dasarathi gouda
April 8, 2011 at 6:26 pm
Good day sir dasarathi just want to ask. I have atx psu and other electronics equipments got repaired by myself. so sir give me some idea about the electronic circuits
and how to find out the faults of the circuits
admin
April 9, 2011 at 1:17 am
Hi Dasarati,
I suggest that you check from the link below because i found it to be good:
http://www.repairfaq.org/sam/smpsfaq.htm
Jestine
pradeesh
April 19, 2011 at 11:51 pm
sir
my system are unread at time not working smps.so pls tell resovle problem
Tapash
April 20, 2011 at 1:29 am
Hello sir this Tapash and it is my first time visiting your site. Just I read about ATX SMPS test and you wrote that give power supply to smps and place a wire across the black and green pins and it will rotate for a while and then totally stop. But I want to know that if it will happen like that so smps is in good condition or need to repair? Please send me mail.
admin
April 20, 2011 at 3:45 am
HI Pradesh,
What is the complaint of the power supply and what have you checked?
Jestine
admin
April 20, 2011 at 3:47 am
HI Tapash,
If the power supply has connected to a board and the fan just rotate a bit and stop then the power supply have problem. If possible connect the power supply to the original board.
Jestine
Sameer SamSol
April 24, 2011 at 4:37 am
Thank you so much.
lie
April 28, 2011 at 6:34 am
I have one problem with the AT power supply. When i connected the power supply to motherboard and turn on the PC and immediately burned the power supply. Second time i was trying with another power supply but before i connect to the motherboard i have check the output and its ok. But once i connected to motherboard again and immediately blow my power supply? so what can be? is my motherboard problem?
admin
April 28, 2011 at 8:20 am
HI Lie,
In that case i suspect the board have problem. But usually power supply will shutdown or no power when tested on a bad motherboard. I suggest that you try on another motherboard.
Jestine
Anil
May 5, 2011 at 12:57 am
Dear Sir,
I have checked for this test then but there is no any response. Fan is not worked for the moment..