[Mr.E]

even though a PSU has no direct connection to a memory unit would it be possible for a failing PSU to wipe out a RAM chip? I have a custom built desktop that has been running decently off and on. From time to time it will just start running much slower and such. I ran memtest and it showed errors. this pair of ram chps is less than 6 months old. I suppose Patriot could have sent me a bad pair but i have a feeling that there is something else that may be causing the sticks to go bad. I have been told before that i may have a failing PSU but all tests went inconclusive so now i am thinking about just switching it out.

But back to the original thought. Is it possible for a failing PSU to cause RAM to defect?

Thanks for your time!

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A power supply supplies power to the computer and all the electronics in the computer, including the memory. There might be voltage regulation on the motherboard, but if there is a problem with the power supply it can affect any and all parts on the computer, depending on whether the problem is with all voltages or just a specific voltage.

[Kemasa]

A power supply supplies power to the computer and all the electronics in the computer, including the memory. There might be voltage regulation on the motherboard, but if there is a problem with the power supply it can affect any and all parts on the computer, depending on whether the problem is with all voltages or just a specific voltage.

[Mr.E]

so in effect it wouldnt affect the memory directly but eventually power would get to the memory, if there were an inconsistency or abnormality then could see anything that that power touches get toasted.. fun stuff..

Edited by Mr.E, 04 May 2010 - 01:45 PM.

[Digerati]

so in effect it wouldnt affect the memory directly but eventually power would get to the memory,

I think there some confusion here. The PSU plugs into the motherboard and so does the RAM. And power for the RAM is routed from the PSU to the RAM. Just because the voltage is carried through a trace on the motherboard instead of power cord plugged into the RAM, the PSU still powers it.

i may have a failing PSU but all tests went inconclusive so now i am thinking about just switching it out.

Well that's the problem, there is no way for normal users to conclusively test PSUs. Here's my canned text on testing PSUs:

To properly and conclusively test a power supply unit (PSU), it must be tested under various realistic "loads" then analyzed for excessive ripple and other anomalies. This is done by a qualified technician using an oscilloscope or power analyzer - sophisticated (and expensive) electronic test equipment requiring special training to operate, and a basic knowledge of electronics theory to understand the results. Therefore, conclusively testing a power supply is done in properly equipped electronic repair facilities.

Fortunately, there are other options that are almost as good. I keep a FrozenCPU Ultimate PSU Tester in my tool bag when I am "in the field" and don't have a good spare power supply to swap in. While not a certain test, they are better than nothing. The advantage of this model is that it has an LCD readout of the voltage. With an actual voltage readout, you have a better chance of detecting a "failing" PSU, or one barely within specified ATX Form Factor Standard tolerances. Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed". Newegg has several testers to choose from. All these testers contain a "dummy load" to fool the PSU into thinking it is connected to a motherboard, and therefore allows the PSU to power on, if able, without being attached to a motherboard - great for testing fans, but again, it is not a true load or suitable for conclusive testing.

Swapping in a known good supply is a tried and trued method of troubleshooting, used for years even by pros. If you have access to a suitably sized, spare power supply, carefully remove the suspect supply and replace it with a known good one and see if the problem goes away.

I do not recommend using a multimeter to test power supplies. To do it properly, that is, under a realistic load, the voltages on all the pins must be measured while the PSU is attached to the motherboard and the computer powered on. This requires poking (with some considerable force) two hard and sharp, highly conductive meter probes into the main power connector, deep in the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it. It is not worth the risk considering most multimeters, like plug-in testers, do not measure, or reveal any unwanted and potentially disruptive AC components to the DC voltages.

Note the required voltage tolerance ranges:

And remember, anything that plugs into the wall can kill. Do not open the power supply's case unless you are a qualified electronics technician. There are NO user serviceable parts inside a power supply.

[Mr.E]

hey Digerati

Actually i knew most of that. You helped a friend of mine with a very similar issue. I already have a frozenCPU tester on the way; expecting it in today or tomorrow. The original problem was thought to be failing memory. but have swapped the original pair of "failing" memory and am having the problems again. Ran Memtest again and go, again, errors from the new pair. so my thought is there is something else causing it to go bad. maybe bad slot, or like you told my friend, failing power supply could lead to all kinds of problems. Afterall, it is the power for the computer and if it is either giving too much or too little power then the MoBo and other parts would either not work or get fried.

but as for my comment, the PSU would directly affect the MoBo and other devices, it isnt plugged into the RAM. However power is channeled to it. I couldnt remember whether or not the MoBo was supposed to have something to help better regulate amount of power sent to the RAM as a precautionary measure. though now that i am thinking about it that sounds more like something you might see on a big OC'ing board. Just maybe anyways...

Thanks for your reply!

[Digerati]

the PSU would directly affect the MoBo and other devices, it isnt plugged into the RAM

Of course not. You never connect a PSU directly to RAM. Think of a light bulb being plugged into an extension cord. The bulb is not directly connected to the wall, but the wall sure is providing the power.

I couldnt remember whether or not the MoBo was supposed to have something to help better regulate amount of power sent to the RAM as a precautionary measure.

All motherboards have regulator circuits, but it is not as a precautionary measure - it is because ALL high-speed digital electronics need stable power. Also note that RAM typically runs on 1.5 to 1.8V - depending on the RAM. A PSU only provides 3.3V, 5V, and 12V. So within the power regulator circuits of ALL motherboards there are also voltage dividers to provide the other voltages not otherwise provided by the PSU. This has nothing to do with the motherboard's quality or feature set. It is simply a requirement for all motherboards.

though now that i am thinking about it that sounds more like something you might see on a big OC'ing board.

Nope. Again, this is a requirement of all motherboards. If the board accommodates overclocking, that simply means the maker provided a means for the user to make minor adjustments to the voltage beyond design specs.

[Mr.E]

ah i see.. xD

i didnt think about that. I knew the different power rails the PSU supplies. Didnt know that RAM only ran on 1.5-1.8V or about the voltage dividers. thats actually kinda cool.. hehe.

Good info!

[Mr.E]

is there any specific procedure to go through when using the frozencpu PSU tester? or just plug it all in and hit the button?

[Digerati]

It did not come with instructions?

Pretty much, that is it. Plug in the PSU and turn it on. If your tester has a switch, the newer ones do, then turn it on too.

[Mr.E]

ok plug in all the cables correct? not just one at a time? it didnt come with instructions, there were instructions on the website that said one at a time.. but that seems like it wouldn't give a "complete" picture of what the PSU is doing

..least thats what is in my mind..

[Mr.E]

reguardless of what i plug in what i am getting is all the rails look to be +/- .2 from their specification except for the -12V Rail. It shows LL on the tester.. could that rail be what is causing me trouble?

[Digerati]

Hmmm, mine came with instructions - though not really needed.

No, you don't have to plug in all the cables (at least not for the primary test). Just plug in the 20/24 pin main motherboard connector.

Don't worry about the negative voltages - just the +3.3V, +5V, and +12V. So it would appear your PSU "may" be good. But as I noted above, those testers are not conclusive.

[Mr.E]

right.

I did do something else, however. I had run memtest and gotten errors the other day. what i did today was swap which slots the memory was in (moved them from slot 1&3 to 2&4) and am running memtest again. Been going for quite some time now with no errors. I suppose it could just be that slots 1&3 went bad. But I would love to know why they went bad... any thoughts?

[Digerati]

Stuff happens.

[Mr.E]

ok still have a pretty slow system that still freezes on me quite often. especially on startup. Memory tested good.. I used both memtest and window memory diagnostic tool thing-a-ma-jig. neither gave any errors what-so-ever. so.. i need a refresher course (mostly cuz i just took an extremely long final for western civilizations class and my brain is fried)... what else might slow the computer down? I have CCleaner run at startup to delete all temp files so i know thats not the problem, I have plenty of disk space and memory(that is actually working), i cannot think of what else might slow the system down.. any ideas? any other hardware that might do this?