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Cheap PSU with pontential?

post #1 of 9
Thread Starter 
Hi guys,

I got a cheap brand new PSU(Approx 650W "App650PS") about 3 weeks ago without guarantee because it's a replacement for another malfunctioning psu(Cooler Master 600W) that lasted for about 2 years.
A few nights back I was gaming, enjoying my new PSU and "BAM" the PC turns off without any warning. I try to turn it on and it won't start but the Mobo light is lit "green". Decided to pull the plug and let everything cool for an hour or so.
After the 1hr wait I plugged the extension cord back in the wall socket and tried to turn on my PC. At this point all I heard was a pop in the PSU and the lights in the whole house went. It tripped the breaker for the whole house.

After opening the PSU it up(no warranty so why not ) I noticed the fuse(5x20mm 6.3A) inside had blown,went quickly to the store and got 3 replacements just in-case. Put in the replacement and "BAM" it blows the second fuse together tripping the breaker for the whole house. It keeps blowing the NTC's too while trying to plug it in.

Made a Dim Bulb Tester to help in testing the unit without blowing it to smithereens every-time I plug it in.

From what I hear it must be a MOSFET that is blew, not sure yet, waiting for my multimeter to test them out. Any suggestion what else to test?

The cheap PSU is rated 650W but i'm pretty sure it doesn't come close this rating considering all parts inside are Chinese,. since it's not under warranty i'm want to fix it and probably tweak it up a little bit so that it runs AT LEAST on it's true rating.

Recapping + anything you guys suggest smile.gifthumb.gif









I you guys need any more pics let me know i'm glad to upload more just let me know what you want to see smile.gif
post #2 of 9

All I want to see is you doing whatever it takes to buy a decent quality-made PSU. I sincerely don't think it's worth trying to make this junker work.

It's a computer!
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i5-2500K @ 4.5GHz (1.368-1.384V fixed voltage) ASUS P8P67 EVO B3 (UEFI ver. 1850) GTX 780 ASUS DirectCU II (1228 / 6300, 1.180V) G.SKILL Ripjaws X 8GB (2 x 4GB) 1866MHz, CL9 
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It's a computer!
(20 items)
 
  
CPUMotherboardGraphicsRAM
i5-2500K @ 4.5GHz (1.368-1.384V fixed voltage) ASUS P8P67 EVO B3 (UEFI ver. 1850) GTX 780 ASUS DirectCU II (1228 / 6300, 1.180V) G.SKILL Ripjaws X 8GB (2 x 4GB) 1866MHz, CL9 
Hard DriveHard DriveHard DriveHard Drive
250 GB Samsung 840 EVO (C:\) 250 GB Samsung 840 EVO (D:\) 150 GB WD VelociRaptor Toshiba 3TB P300 
Optical DriveOptical DriveCoolingOS
Samsung SH-S243N 24x DVD Burner Samsung SH-S203N 20X DVD Burner Thermaltake Frio Win 7 Home Premium x64 SP1 Retail 
MonitorKeyboardPowerCase
AOC G2460PG (24" 1920 x 1080 144Hz G-SYNC) Filco Majestouch 104-key Cherry MX Blues w/NKRO Corsair HX650 (Bronze, ordered on 12-12-2009) CM 690 
MouseMouse PadAudioAudio
Intellimouse Optical (1.1A) 1000Hz polling rate Basic, but premium round X-Fi Titanium HD Klipsch ProMedia 2.1 (with 16 AWG Monster Cable... 
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post #3 of 9
You don't even know yet if maybe the psu also took some other compontents into the grave. Depends on the rest of your system but I wouldn't take the risk of running a low end modded psu.
Minerva
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Minerva
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post #4 of 9
Re caping is pointless but changing power transistors can work it depends what is blown. can u see burned components ?
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WD wd10ezex WD wd10ezrz Samsung evo 840 250Gb  Samsung evo 850 500Gb 
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WD wd10ezex WD wd10ezrz Samsung evo 840 250Gb  Samsung evo 850 500Gb 
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Samsung evo 850 500Gb Alphacool eisbaer 280 Windows 8.1 DELL U2515H 
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Compaq GYUR86SK PS/2 Multimedia Keyboard SK-286... Seasonic G Series G-650 Corsair Carbide Air 540 Logitech G402 
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post #5 of 9
Thread Starter 
I don't see anything burnt except the fuse and a few themistors that I kept replacing, i have gone through a couple of those and NTC thermistors because they kept blowing once trying to power on the system with a new fuse and thermistor:heyyou: . i made a Dim BTulb Tester and placed a fuse holder on the pcb to make toubleshooting easier . I've heard from a number of guys that it is the transistors/MOSFETS that could be toast. Not sure though til I test them myself with a DMM.

Here are the specs for the old/stock Chinese transistors
13N50 http://www.pcaxe.com/slike/hardver/n...F/GPT13N50.pdf.

I want to replace them with these
FQP12N60C
N-Channel QFET®MOSFET 600 V, 12A, 650 mΩ
http://www.farnell.com/datasheets/1827138.pdf

Do you think it is any good?
post #6 of 9
Thread Starter 
TwoCables : Yeah i feel you man smile.gif Wish I could, that would be the first thing I would do. For now I have this little junk to tinker with rolleyes.gif I wonder how much juice i can make it produce at a stable MOD.
Edited by PSUtweaker - 10/20/15 at 6:02am
post #7 of 9
Quote:
Originally Posted by PSUtweaker View Post

I don't see anything burnt except the fuse and a few themistors that I kept replacing, i have gone through a couple of those and NTC thermistors because they kept blowing once trying to power on the system with a new fuse and thermistor:heyyou: . i made a Dim BTulb Tester and placed a fuse holder on the pcb to make toubleshooting easier . I've heard from a number of guys that it is the transistors/MOSFETS that could be toast. Not sure though til I test them myself with a DMM.

Here are the specs for the old/stock Chinese transistors
13N50 http://www.pcaxe.com/slike/hardver/n...F/GPT13N50.pdf.

I want to replace them with these
FQP12N60C
N-Channel QFET®MOSFET 600 V, 12A, 650 mΩ
http://www.farnell.com/datasheets/1827138.pdf

Do you think it is any good?
make sure u keep transistors same specs and its good enough and also check temperatures of the radiators when transistrs replaced.
My System
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CPUMotherboardGraphicsRAM
i7 4790k Gigapyte gaming 5 GeForce® GTX 1080 Ti Gaming OC 11G 16gb 1600mhz CL9 Crucial Ballistix Sport  
Hard DriveHard DriveHard DriveHard Drive
WD wd10ezex WD wd10ezrz Samsung evo 840 250Gb  Samsung evo 850 500Gb 
Hard DriveCoolingOSMonitor
Samsung evo 850 500Gb Alphacool eisbaer 280 Windows 8.1 DELL U2515H 
KeyboardPowerCaseMouse
Compaq GYUR86SK PS/2 Multimedia Keyboard SK-286... Seasonic G Series G-650 Corsair Carbide Air 540 Logitech G402 
Mouse PadAudioOther
a4tech gaming x7 logitech x-530 + JBL GT series gt5-1204br and P... bitfenix recon 
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My System
(20 items)
 
  
CPUMotherboardGraphicsRAM
i7 4790k Gigapyte gaming 5 GeForce® GTX 1080 Ti Gaming OC 11G 16gb 1600mhz CL9 Crucial Ballistix Sport  
Hard DriveHard DriveHard DriveHard Drive
WD wd10ezex WD wd10ezrz Samsung evo 840 250Gb  Samsung evo 850 500Gb 
Hard DriveCoolingOSMonitor
Samsung evo 850 500Gb Alphacool eisbaer 280 Windows 8.1 DELL U2515H 
KeyboardPowerCaseMouse
Compaq GYUR86SK PS/2 Multimedia Keyboard SK-286... Seasonic G Series G-650 Corsair Carbide Air 540 Logitech G402 
Mouse PadAudioOther
a4tech gaming x7 logitech x-530 + JBL GT series gt5-1204br and P... bitfenix recon 
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post #8 of 9
Thread Starter 
Quote:
Originally Posted by mfdoom7 View Post

make sure u keep transistors same specs and its good enough and also check temperatures of the radiators when transistrs replaced.
Ok thanks for the tip, so are the one's posted above good enough ? I tried selecting from the available ones that is closest to the original ones in the psu. Will this work?

When measuring Temps with the DMM what ranges should be considered optimal and which one's are high? I noticed white paste on the heatsinks, Is that the same as thermal paste for cpu's and can I use that on the back of the transistor? smile.gif
post #9 of 9
Quote:
Originally Posted by PSUtweaker View Post

Ok thanks for the tip, so are the one's posted above good enough ? I tried selecting from the available ones that is closest to the original ones in the psu. Will this work?

When measuring Temps with the DMM what ranges should be considered optimal and which one's are high? I noticed white paste on the heatsinks, Is that the same as thermal paste for cpu's and can I use that on the back of the transistor? smile.gif
yea it will work. but i recomend u to use thermal pads not paste if u have non isulated transistors but if its all black then thermal paste is good. u dont want to short transistors out biggrin.gif
My System
(20 items)
 
  
CPUMotherboardGraphicsRAM
i7 4790k Gigapyte gaming 5 GeForce® GTX 1080 Ti Gaming OC 11G 16gb 1600mhz CL9 Crucial Ballistix Sport  
Hard DriveHard DriveHard DriveHard Drive
WD wd10ezex WD wd10ezrz Samsung evo 840 250Gb  Samsung evo 850 500Gb 
Hard DriveCoolingOSMonitor
Samsung evo 850 500Gb Alphacool eisbaer 280 Windows 8.1 DELL U2515H 
KeyboardPowerCaseMouse
Compaq GYUR86SK PS/2 Multimedia Keyboard SK-286... Seasonic G Series G-650 Corsair Carbide Air 540 Logitech G402 
Mouse PadAudioOther
a4tech gaming x7 logitech x-530 + JBL GT series gt5-1204br and P... bitfenix recon 
  hide details  
Reply
My System
(20 items)
 
  
CPUMotherboardGraphicsRAM
i7 4790k Gigapyte gaming 5 GeForce® GTX 1080 Ti Gaming OC 11G 16gb 1600mhz CL9 Crucial Ballistix Sport  
Hard DriveHard DriveHard DriveHard Drive
WD wd10ezex WD wd10ezrz Samsung evo 840 250Gb  Samsung evo 850 500Gb 
Hard DriveCoolingOSMonitor
Samsung evo 850 500Gb Alphacool eisbaer 280 Windows 8.1 DELL U2515H 
KeyboardPowerCaseMouse
Compaq GYUR86SK PS/2 Multimedia Keyboard SK-286... Seasonic G Series G-650 Corsair Carbide Air 540 Logitech G402 
Mouse PadAudioOther
a4tech gaming x7 logitech x-530 + JBL GT series gt5-1204br and P... bitfenix recon 
  hide details  
Reply
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