1. ## Suspect ATX Voltages

Hi

For some time now, when the pc is powered up (linux or XP) it often freezes whilst loading OS (shows desktop). A reboot fixes but looking at voltages within BIOS shows the following for my Corsair VX550 (about 2 years old):

VCore = 1.467V
+3.3V = 3.403
+5V = 5.16V
+12V = 12.281V
Running old 3800+ venice chip but either the motherboard is suspect, BIOS readings or PSU not good enough. Bought it as voltages were very close to targets. ATX here

Using 3 Hard drives, 1 DVD and GTX 460 graphics card.

TIA

2. ## Re: Suspect ATX Voltages

ATX specifications state that safe limit is +/- 10% I think.
3.3+0.33 = 3.63 so all good
5+0.5 = 5.5 so all good
12+1.2 = 13.2 so all good

3. ## Re: Suspect ATX Voltages

I know it is within limits but 500mv out! and thought Corsair had tight volts so not happy they are so far off what reviews said.

4. ## Re: Suspect ATX Voltages

nothing wrong with that, and unless you have a calibrated multi meter you have no idea the shown voltages are correct. just because its built into the motherboard does not mean its accurate.

5. ## Re: Suspect ATX Voltages

The ATX voltage specifications are shown here. Most are +/_ 5% apart from -12v (if provided) and +12V which can drop by 10% under full load.

Table 2. DC Output Voltage Regulation
Output Range Min. Nom. Max. Unit
+12VDC (1) ±5% +11.40 +12.00 +12.60 Volts
+5VDC ±5% +4.75 +5.00 +5.25 Volts
+3.3VDC (2) ±5% +3.14 +3.30 +3.47 Volts
-12VDC ±10% -10.80 -12.00 -13.20 Volts
+5VSB ±5% +4.75 +5.00 +5.25 Volts

(1) At +12 VDC peak loading, regulation at the +12 VDC output can go to ± 10%.
(2) Voltage tolerance is required at main connector and S-ATA connector (if used).
As Gonz0 says, the onboard voltage sensor may not be accurate - the only way to test the PSU is using a calibrated test meter,

Which voltages are 500mV out? Looking at your post, all are within 300mV of the stated voltage and the 3.3 and 5V rails are also within the tolerance at 103 and 160 mV respectively.

6. ## Re: Suspect ATX Voltages

Was in a rush - 280mv on 12V rail.

Just that the computer locks up and voltages not seemingly accurate. Speedfan shows same.

Maybe upgrade motherboard as that could be at fault in not regulating maybe.

Cheer guys

7. ## Re: Suspect ATX Voltages

Speedffan will get the same information from the on-board sensors. But having a slight over voltage is better than a slight under voltage,and in itself is very unlikely to cause the machine to lock up. PSU's will tend to be slightly on the high side to allow for voltage drop in the power leads at maximum load (although a really good PSU should sense the output voltage at the connectors to improve regulation - few do)

So if it is locking up, I'd look at some other cause.

Have you run Memtest? Faulty or failing memory can be a cause of lock ups and is easy to test.

8. ## Re: Suspect ATX Voltages

On the subject of memtest where can I get the exe version? I used to have it but can't find it (not that i've tried that hard). my pc seems to be stable only with 1 dimm in which is... annoying...

9. ## Re: Suspect ATX Voltages

http://www.memtest.org/#downiso

I don't think there is a .exe as such (.exe is only one of several designations for executable binary code in file in a DOS/windows like environment) The iso allows you to create bootable media which then runs the application binary directly.

nibbler (02-10-2010)

11. ## Re: Suspect ATX Voltages

Thanks for the info.

Having trouble with new GTX 460OC from Scan. Running Kombuster sometimes works but sometimes freezes computer. Got MW2 to run multiplayer for about 30secs then froze with high pitched squeal.

Not convinced of PSU but would GFX card do this? Suspect power draw as this card needs two inputs and my 4830 didn't do this (one input)

12. ## Re: Suspect ATX Voltages

if it needs 2 and your using one then its new PSU time m8.

13. ## Re: Suspect ATX Voltages

Originally Posted by geezerone
Thanks for the info.

Having trouble with new GTX 460OC from Scan. Running Kombuster sometimes works but sometimes freezes computer. Got MW2 to run multiplayer for about 30secs then froze with high pitched squeal.

Not convinced of PSU but would GFX card do this? Suspect power draw as this card needs two inputs and my 4830 didn't do this (one input)
Your VX550W should be fine with a GTX460. Also, a GTX460 with a single core AMD Athlon 3800+ seems a very unusual combination. Updating your CPU,motherboard and RAM would have been a better use of your budget.

14. ## Re: Suspect ATX Voltages

2xPCI-E psu connectors are on a VX550 and even tried a molex to 6 pin converter to no avail.

Part of the bigger plan Cat. My 4830 resides in another upgraded pc with 19" monitor which had no graphics card.

For now I am in a dilemma as to whether the GPU is suspect, PSU or other. Used to lock up when first booted on occasion before the new GPU added but not the GPU lockup hence reservations about psu.