My +5v only outputs 3,47V ???!!!

[unregistrd]

i was going thru the posts on this forum when i read this posted by bigben2k

"5%:
12V line: min 11.4, max 12.6
5V line: min 4.75, max 5.25

3.3 line: min 3.14, max 3.47"


i'm currently using Motherboard Monitor 5.1.9.1 and it says the following things :

Core 0 : 1,69V
Core 1 : 2,48V
+3.3 : switches between 3,28V and 3,30V
+12.00 : switches between 11,86V and 11,98V
-12.00 : switches between -10,38V and -10,44V
+5.00 : 3,47V
-5.00 : -5,22V


is this bad or doesn't it matter or what does it do?

i also have problems when writing directly from DVDROM to CDRW. my DVDROM stops working (no power) until i turn off my pc. and my cdwriter keeps burning and reading. (??!!)

are these two things linked together or is it both something else? (the PSU and the dvdrom problem)

---------------

my system:

amd athlon xp 1600+
Elitegroup K7S5A motherboard
2x 256 MB DDRram
30gb hdd (seagate)
ACER 16x 40x dvdrom
ACER 10x8x32x cdwriter
HEC-300LR-PT (300W PSU)

nothing modded (yet). no bells or hp pc. i bought all the pieces myself and put it all together.

[bigben2k]

Off hand, it looks like you have a problem. To confirm it, you should get a voltmeter to check what your 5V line is outputting.

It certainly would explain your problem.

[unregistrd]

i've got a voltmeter right here

i guess i should put it on 20v DC but where can i and should i measure the voltage?

and how can i fix this problem if the volt meter confirms it?

btw: thanks for helping me out

[bigben2k]

You're welcome.

I'd just go ahead and measure all of them, until you hit the 5V line. Otherwise, you're looking at the following pins.

pin 1-3-16-17 or 18: +5V line (they're all connected together)
pin 2-4-9-10-12-13-14: ground (they're also all connected together)

[unregistrd]

ok, after i short-circuited my PSU a few times (do you know that they just turn on along with some of the hardware ) i now know that there isn't anything wrong with it. it says 4,94V just like it does in the bios.

but then why does Motherboard Monitor say that it only outputs 3,47V ?

and how come the dvdrom and cdwriter can't work at the same time?

do i need a stronger PSU? (400W for example) and how can i calculate how many watts my pc is using of the 300W PSU ?


and if someone could tell me some good diagnostics / overclock programs / sites i would certainly appreciate it

and tnx for the great pic bigben2k

[bigben2k]

Hey, don't thank me, thank the random site I chose that had the pic...

[unregistrd]

thanks random site

[bigben2k]

Originally posted by unregistrd
but then why does Motherboard Monitor say that it only outputs 3,47V ?

and how come the dvdrom and cdwriter can't work at the same time?

do i need a stronger PSU? (400W for example) and how can i calculate how many watts my pc is using of the 300W PSU ?


and if someone could tell me some good diagnostics / overclock programs / sites i would certainly appreciate it

and tnx for the great pic bigben2k

MBM: I'd try checking the configuration of MBM, to see if the 5V indicator is linked to the 5V sensor.

DVD+CDRW: I suspect a power failure. Your PSU 300W may be on the weak side, for everything that you are running. What you can do (if you've got more CDs to sacrifice!) is monitor the voltage on that 5V line, while you're CD-writing. If the 5V line drops below 4.75 or dips quickly, then you know that the PSU just can't handle it. If it doesn't, then I'd suspect either an incompatibility problem (try using separate channels) or a driver issue (get the latest one).

Otherwise, your PSU should be OK, but I can't say for sure. Personally, I've picked a 430W PSU, just because I don't want to deal with any of this...

[unregistrd]

MBM : the sensor is linked correctly

dvdrom : i'll check tomorrow morning/afternoon when i've got some time.

i'll also check if there are any new versions of the program and of my drivers (all of them)

well now i would pick a better one too, but at the time i didn't have money for a better one and this one would normally do the trick. it did the trick for the past half year so...
i'd say my PSU was going to die but on the old pc here the PSU is like antique (it's at least 8 years old) and it still works perfectly.

[Brad]

I'd just say that mbm5 is just confusing itself, 4.94v is obviously the correct 5v reading.

I personally own a CWT 550w psu. it is the exact same as the Antec True power 550w, but it doesn't have the fan output molex headers and is about NZ$120 cheaper

[resago]

uh, test the 5V line with your computer ON and everything hooked up there chief.

[Zoolander]

hey,

The only thing you have to watch out for when you're testing out your powersupply is the ramping up and down of the voltage.

yeah voltage will fluctuate, this is do to the nature of digital/analog devices turning off and on. The fluctuation is further caused by the powersupply attempting to regulate the circuit, and caps discharging/charging (typically this is the purpose of capacitors to reduce a drop or rise in voltage). To further prove this, check your mobo around the processor, you'll see quite a few caps (small ones).

However, at a certian point the power drain will be overwhilming for the powersupply, and this will cause a lack of current to your devices. When this happens... you have a hard reboot.

Another thing that I didn't mention is the equipment that you are using to do your testing. Everyone has probably read the specs on what equipment is good and what equipment is bad. But you really don't know how accurate your equipment is. Altough there is a way to test how accurate your DMM's/voltage monitors are.

If you guys want, I'll make a post on how to test your equipment, properly, to show the true accuracy of the meter's.

Davis

PS: Brad was right, 4.94 volts is the 5v line. Components on a board will operate in a range of values around 5v. Just remember, the components on your mobo are all digital, meaning they run on discrete values of 1 or 0 (4.94 volts or zero), so it doesn't matter if it fluctuates a little, that's the beauty of digital.

[bigben2k]

That's why I prefer the old style meters, the ones with a needle. Forget the digital display ones, they're useless.

A scope is even better, but mucho $$$

[jaydee]

Originally posted by resago
uh, test the 5V line with your computer ON and everything hooked up there chief.

Thats what I was going to say! Does you no good to test the PSU if the power is not being drawn from it. Try a different monitor and then watch it when you fire up the CD DVD drives ect and see if it drops.