Cause USb port voltage overcurrent motherboard ASrock H81m VG4 R2.0

[thery2003]

Mobo ASrock H81m VG4 R2.0
Samsung DVD RW
DDR 3 kingston
processor Intel G3240
Enlight sniper power supply 430 watt

Bios shows +5V =5.256V to 5.28 V
Multimeter +5V =5.18V to 5.23V loading voltages with 1 sata power connect to hard drive (test to 4 pin molex)
Multimeter +5V=5.25V to 5.28 loading voltages with 1 sata power connect DVD RW (test to 4 pin molex)
Multimeter +5V= 5.33 V test using jumper psu idle
USB Voltmeter +5V= 5.25V to 5.51V fluctuation( rear usb 2 and 3 port of the motherboard)
USB Voltmeter +5V = 4.78 V to 5.15V fluctuation (Front usb port)
Can any one let me know is that anyhing wrong with above number?
what cause usb port voltage overcurrent,,,,is the power supply problem or the motherboard

 

[R_1]

so what's the problem here?
all voltage specs are in a range of +/- 5%. so 5.25V is in spec so is 4.75V, that half a volt is the natural range of the USB Spec
those look fine to me

I would however suggest a better quality PSU

 

[thery2003]

+5V= 4.75v to 5.25v is the tolerance ranges

but my question is my psu +5V voltage is above of the tolerances ranges,,such as usb port above 5.25V to 5.51V (could kill usb port devices)
and also loading PSU voltages shows on sata power connect to DVD RW is 5.25 V to 5.28V could kill DVD ROM
Is not that out of the tolerance ranges

 

[R_1]

+5V= 4.75v to 5.25v is the tolerance ranges

but my question is my psu +5V voltage is above of the tolerances ranges,,such as usb port above 5.25V to 5.51V (could kill usb port devices)
and also loading PSU voltages shows on sata power connect to DVD RW is 5.25 V to 5.28V could kill DVD ROM
Is not that out of the tolerance ranges

it is also within the error range of all the equipment measuring. it is so close I would not worry. if you were reading 5.9 and above then yeah you got an issue.
the only number that gives me pause is "USB Voltmeter +5V= 5.25V to 5.51V fluctuation" and that fluctuation is from the low quality power supply.
the 5.28V will be in spec after the resistance of the cable between the plug and the DVD, you see the resistance the front panel header incurs. if you are concerned only plug devices with a cable into that plug (5.51V intermittent)

one number may be a bit out of spec but taken as a whole it looks fine considering the PSU driving them.

 

[thery2003]

Can u give me number,,,how many maximum voltage each rail from PSU that motherboard design to hold with damaging the component from power supply....

 

[R_1]

3.3V +/- 5% I give an extra 2% for Margin of error so 3.1 to 3.5V
5V +/- 7% 2 for MOE 4.65 to 5.35V
12V +/- 7% 11.2V to 12.8V

beyond these numbers I start to get concerned, and only one of your reading was out of spec.
A better PSU is my suggestion for next upgrade though.
seasonic s12II 420w or CX450M are my suggestions for budget high quality units

 

[thery2003]

within the number voltages that u write,,,would it be cause pc running a problem such as freeze and unfreeze randomly ?

 

[R_1]

random freezes and hangs are usually software, RAM, or shorts.
software - make a USB linux drive and boot to it, get online and look for the freeze, if the freeze issue follows to a new environment the issue is hardware. if linux plays fine you can remove the hardware from suspicion.
RAM - on the linux drive it should have memtest86 that you can run, this is a memory test let it go for 2 passes and look for errors. no errors and the RAM is good
Shorts make sure there are no extra standoff behind the motherboard, no screws rolling around the case, look for anything touching that shouldn't

 

[thery2003]

thanks for ur reply,,,, i will upgrade my power supply better one since this power supply has issue

 

[thery2003]

about +5V usb port voltages

5.25V to 5.51V i check with Mayuan usb voltmeter(this device is not accurate)
and i check with other keweisi voltmeter shows +5V 5.13 to 5.15 V abit better
with i check with digital multimeter voltmeter shows +5V 5.20V to 5.24V most accurate