Power Supply Problems

[Lone Gunman]

So I've been having some problems with low voltage on the 3.3v rail on multiple desktop systems I have. I posted a screen shot pic so you could see what I'm talking about. Note that in the Hardware Monitor section of BIOS it says that the 3.3v rail is only 3.024v and when I check it at the ATX plug on the motherboard with my volt ohm meter I get 3.11v which is a little more but is still low??

FYI, I currently have 4 desktop systems that have very similar hardware and all are showing the similar problem with some difference in that voltage. That and I just got 2 NEW 650watt ATX power supplies one of which is the one with that 3.024v reading.

Hardware is as follows:

Asus P5Q Pro socket 775 motherboard with a Xeon x5460 CPU @3/16ghz
G.SKIL 8GB 4x 2GB DDR2-800 PC2-6400 RAM
ATI Radeon x1650 PCIe video with 512mb RAM
4 SATA hard drives and 2 SSDs (this varies between systems)
PCIe 4 port USB 3.0 add in card
And I have run power supplies up to 750watt with the same results. Just thought with this old hardware I could get by with the smaller 650s so I bought a couple.

So what do ya think is going on here? Any ideas?

Thanks

 

[Cham]

Seems low for sure. What is your line voltage (mains), both legs, each side, etc? Have to start at the line voltage coming into your house and work your way to the load. Computer power supplies are supposed to be very well regulated but low AC in might be a limitation.\

My current line voltage at the wall outlet is 114VAC currently, a bit low as well.

here's my voltages on the desktop I am using right now:

 

[FTA4PA]

So I've been having some problems with low voltage on the 3.3v rail on multiple desktop systems I have. I posted a screen shot pic so you could see what I'm talking about. Note that in the Hardware Monitor section of BIOS it says that the 3.3v rail is only 3.024v and when I check it at the ATX plug on the motherboard with my volt ohm meter I get 3.11v which is a little more but is still low??

FYI, I currently have 4 desktop systems that have very similar hardware and all are showing the similar problem with some difference in that voltage. That and I just got 2 NEW 650watt ATX power supplies one of which is the one with that 3.024v reading.

Hardware is as follows:

Asus P5Q Pro socket 775 motherboard with a Xeon x5460 CPU @3/16ghz
G.SKIL 8GB 4x 2GB DDR2-800 PC2-6400 RAM
ATI Radeon x1650 PCIe video with 512mb RAM
4 SATA hard drives and 2 SSDs (this varies between systems)
PCIe 4 port USB 3.0 add in card
And I have run power supplies up to 750watt with the same results. Just thought with this old hardware I could get by with the smaller 650s so I bought a couple.

So what do ya think is going on here? Any ideas?

ThanksView attachment 155991

I have seen some tolerance figures that quote plus or minus 4%, others 5%. This one, ATX v2.2, states 5%:

https://cdn.instructables.com/ORIG/FS8/5ILB/GU59Z1AT/FS85ILBGU59Z1AT.pdf

That would be 3.135v to 3.465v so even with the tolerance figured in it is definitely lower than spec. I noticed in another thread you said your power sucks and you used a power conditioner to rectify an fta receiver problem. Since you said this affects multiple systems I'm wondering if your power problem is entering into it, although strange that the 5V and 12V are in range. Do you have a power conditioner on your computers?

You might also try turning off your computer(s) for a few hours then testing the voltages immediately upon start and then again several hours later to see how the readings differ. If it is good at start but drops later it is an indication of a failing power supply. Perhaps the poor power at your location is slowly damaging your computer PSUs? Keep us posted and good luck!

 

[Lone Gunman]

"That would be 3.135v to 3.465v so even with the tolerance figured in it is definitely lower than spec. I noticed in another thread you said your power sucks and you used a power conditioner to rectify an lnb problem. Since you said this affects multiple systems I'm wondering if your power problem is entering into it, although strange that the 5V and 12V are in range. Do you have a power conditioner on your computers?"

Yes, I had also found that 5% tolerance number.

Well, I really don't remember anything about a "power conditioner" for an lnb problem?? Sorry but at 76 years old I find myself forgetting more and more stuff as the days go by!

I checked several receptacles from one end of the house to the other and found 123/124volts on all of them so I guess that eliminates that as a problem.

And one more thing...............does the motherboard have a way to regulate that 3.3v rail independent of the actual power supply itself?

Just a thought...................

 

[harshness]

First off, I'd suggest you address the line voltage issue. If your meter is features RMS, it may be hiding something nasty in terms of steady voltage.

A good UPS with AVR should bump up the line voltage to a proper level.

3.3V is usually used by RAM and M.2 SSDs. It is available on PCIe but I can't imagine that your USB adapters would consume that much (if any) 3.3V power. Removing them temporarily could pin that down.

 

[Lone Gunman]

First off, I'd suggest you address the line voltage issue. If your meter is features RMS, it may be hiding something nasty in terms of steady voltage.

Forgive my ignorance but I don't know what you mean by this? When you say "line voltage" is that in reference to the 123v wiring in my house or what? And I have no idea what "features RMS is?

3.3V is usually used by RAM and M.2 SSDs. It is available on PCIe but I can't imagine that your USB adapters would consume that much (if any) 3.3V power. Removing them temporarily could pin that down.

And yes, I did remove that USB 3.0 add in card and there wasn't much of a change at all.

 

[TheKrell]

I'm not harshness, but I'll take a swing at these questions.

When you say "line voltage" is that in reference to the 123v wiring in my house or what?

Yup.

And I have no idea what "features RMS" is?

It is an acronym for "root mean square". It is a typical measure of average voltage you get from a voltmeter. Any average can hide "something nasty" like voltage spikes of short duration.

 

[medvyed]

I'm not harshness, but I'll take a swing at these questions.

Yup.

It is an acronym for "root mean square". It is a typical measure of average voltage you get from a voltmeter. Any average can hide "something nasty" like voltage spikes of short duration.

Through my homeowner's insurance (State Farm), I have a device/app that I believe can identify the short-duration voltage spikes you mention. Once hooked up, it measures line voltage and other parameters dynamically and reports any dangerous anomalies.

The device/app is called Fing. It is from a company called Whisker Labs. Go to Home for more info.

Below you can see my monitoring screen.

 

[TheKrell]

Through my homeowner's insurance (State Farm), I have a device/app that I believe can identify the short-duration voltage spikes you mention. Once hooked up, it measures line voltage and other parameters dynamically and reports any dangerous anomalies.

I also have State Farm. Did you get a discount?

 

[medvyed]

I also have State Farm. Did you get a discount?

State Farm paid 100% of the cost of the Ting box and 3 years of the concierge monitoring service.

From the tingfire site: How to Get Ting

 

[harshness]

This Ting device sounds like something that I've been looking for. I was looking at recording meters but the Ting is a lot smarter than that.

The monitoring part annoys me as I don't typically candle to monitoring fees for anything and have all sorts of server capacity for stuff like this.

 

[Lone Gunman]

Update:

Well, I did some rechecking this morning. I actually have two meters, one Fluke 7-600 and one Omega HHM93 and both those meters give me the same voltage at the receptacles. I even went so far as to go to my neighbors house, which is a half mile down the road and checked his and got the same 123v at his house that I got at mine. And just so you know, my electric service comes from CVEC and his comes from Appalachian Power so he's on a different line from me but both check the same.

Then I found this:

What is allowable voltage range at a wall receptacle outlet in a house?

www.howtolookatahouse.com

The nominal voltage in the United States is 120 volts, but the National Electrical Code [NEC 210.19 (A)] specifies an acceptable drop of 5% to fartherest outlet, which is 114 volts. The NEC does not specify maximum voltage, but plus 5% is the accepted standard. This puts the acceptable voltage range of a nominal 120-volt receptacle at between 114 and 126 volts.

You will rarely get a reading of exactly 120.0 volts. Voltage is typically set a little higher at the tap at the electric utility’s transformer to allow for voltage drop between it and the residence. The farther away the house is from the a transformer, the more the voltage drop. Then there is secondary voltage drop induced by the wiring between the main electric panel and a receptacle.

We test the voltage at a receptacle as part of an inspection, along with resistance to ground. An example of an acceptable reading is shown below.

As for the Ting thingie.............I can hear my insurance agent now when I tell him I want them to pay for that!!

Just saying....................

 

[arlo]

Maybe these things have been addressed already.
I have the same processor in a Gigabyte socket 775 mobo.
I found a modded bios to support the processor and memory better.
It plays nicely and although I'm not really an overclocker, found that it would a bit and runs stable.
Not something the processor exactly supports. But the bios provides for some tweaks.
I also have an Asus X58 Sabertooth socket 1366 motherboard that I very recently put a Xeon X5690 and a pile of ram in.
It runs very well stock. I dug up a modded bios for it to better support Intel microcode. I pumped it up to 4.3 GHz just for the hell of it. It's back to stock now and is very stable.
Both have Antec power supplies.
Have you tried going into the AI Tweaker to get your voltage rails up to your par?
And they are not new boards. Don't discount that they may have drifted capacitors. Even though Asus makes one hell of a nice mobo.
Lastly. SMPS do a nice job with regulation even with large input voltage swings.
Your 3.3v rail does seem low.
I guess in my world I would put a current draw on it while connected to the mobo and see how much of a current draw I could put on it before it started to drag down. What is your PS voltage rail wattages speced at?

 

[Lone Gunman]

I've been running those x5460 CPUs on those Asus P45 chipset boards now for 5 or 6 years now and never really noticed any issues until the past year or so. The first one I did was on a P5 K Pro board with a P35 chipset, which I still have and it worked fine, and, I'm still using that one too only with a regular Pentium IV cpu @ 3ghz.

Have you tried going into the AI Tweaker to get your voltage rails up to your par?

Yup, when I first saw that low 3.3v rail I went looking but never did find anything that I thought would fix that. Any suggestions and I may give it a look again. Oh and the PSUs I'm running now vary between 100 to 115 watts on that 3.3v rail.

And speaking of over clocking..............my first was some socket 370 cpus and then I did a Slot 1 300a Celeron that I overclocked to 450mhz and ran it like that for a few years. In fact, I think I still have that processor in my junk drawer. I haven't done any of that in years though. Just haven't felt the need for it.

Oh, and where did you get those "modded" BIOS chips?

Just saying.................

Oh, and one last thing.......what should I look for in a reasonibly priced uninterruptible power supply or a surge protector for a desktop? I may give that a try as well if they don't cost me an arm and a leg.

 

[FTA4PA]

Yes, I had also found that 5% tolerance number.

Well, I really don't remember anything about a "power conditioner" for an lnb problem?? Sorry but at 76 years old I find myself forgetting more and more stuff as the days go by!

I checked several receptacles from one end of the house to the other and found 123/124volts on all of them so I guess that eliminates that as a problem.

And one more thing...............does the motherboard have a way to regulate that 3.3v rail independent of the actual power supply itself?

Just a thought...................

Oh, and one last thing.......what should I look for in a reasonibly priced uninterruptible power supply or a surge protector for a desktop? I may give that a try as well if they don't cost me an arm and a leg.

You are not getting too old but apparently I am. I had several tabs open and associated another user's power issues with yours.

Point I was trying to make was to install a line conditioner/UPS to see if it fixed your issues. I have UPS's from Cyberpower, APC and Belkin and all do I fine job of regulating the power. Just buy one that has enough 'juice' to support your equipment that will be hooked to it.

 

[Lone Gunman]

OK it's been a few days and I've got some additional info concerning that CX650M Corsair power supply. But first here's a picture of the BIOS hardware monitor showing voltage on that +3.3v circuit with that new "off brand" 650watt power supply. Notice that 2.992v on that +3.3 rail??



Voltage at the motherboard plug showed +3.1v

So then I took that Corsair and connected just the main and CPU connectors and checked that one and here is what that one looked like.



It's still a little low cuz that Corsair measures +3.32 with the meter but it's way better than the Fleabay junk that's in it now @ 3.280v. I've got to order a couple of SATA cables for it before I can install it cuz I didn't get those when the guy gave it to me but at this point I'm sure it's worth the $20 those cables will cost me.

 

[Lone Gunman]

UPDATE: Got those cables I needed the other day then installed everything like it needed to be and guess what? Booted up in Linux Mint and ran for about 5 minutes then there was a "click" and I looked and the monitor was black, then the computer proceeded to reboot to only power off again and restart continually?? WTF?? I guess it's got an over current problem that I won't be able to fix. CRAP!!

So, I guess I'm done with that Corsair power supply and will have to go ahead and buy a new something or other, but in the mean time, I put that "cheap china junk" 650watt one back in and I'm using it now so I may just ride this one until it pukes!

Oh, and thanks for trying to help with this.

Just saying................

 

[harshness]

It probably isn't worth chasing down problems with a seven year old computer even if it was once a beast.