Computer Restarts Randomly when I do anything that actually matters...

[bekka]

Since the hardrive and Windows XP installation are new (within 24 hours) I'm hoping those of you in the know (which emphatically does not include me) could help me.  My computer is 4 years old so I'm not even sure what I put in it, but the motherboard and graphics card are Nvidia (nforce 2 and geforce fx 5200 respectively). AMD 4something chip.

Problem is this:  restarting Windows is random, I can be on the internet for hours, but try to install Sims and it resets.  Also restarted when copying files from old hard drive to new one.  This problem started when I came back from two week holiday and computer refused to start at all.  I turned off the power supply and turned it back on and it started, but hours later restarted and windows claimed missing file.  I tried to repair using installation disk but computer constantly restarted in the middle of installation (a total of 18 times before I gave up).  New drive allows windows to work but still restarts at inopportune times.

I could install Norton Systemworks, but the Sims will not install, it keeps restarting.  I have limited funds and fear a hardware problem.  Any help with either how to diagnose the problem or educated guesses as to the problem component would be greatfully acknowledged.

[Hegelian]

Spontaneous reboots are usually (although not always) the result of power-supply problems. If your PC is four years old and came with a standard no-name low grade power supply, it may be that you're not getting enough clean power to your components. It would surprise me some if the new hard drive alone was drawing so much more power to make this manifest, but odder things have happened.

At the least, I would open up the case and make sure all the power connections are tight, including the ones to the motherboard.

[KatEnigma]

It could also be a heat problem. Get a can of compressed air and blow out all the dust from the inside of the case, and make sure there's plenty of airflow around it. Also, make sure the fans are all working. It's probably power, though. Especially since it restarted while trying to copy over to the new HD. If you were running close to the limit of what your PSU can handle, the HD would be enough to make it start crashing.

[bekka]

@Hegelian:  I had been thinking along those lines, so I'm glad to have my musings confirmed.   I checked the things I could see easily and they don't appear loose, but I read the side of the power supply and it appears to only be 150W.  I'm guessing that is in the pathetic range, it came with the case and I don't even know if it can be removed.  I'll actually take a better look tomorrow since even with the light from the ceiling light its very dim in here at night.

@KatEnigma:  When the hard drive was replaced my tech (read Dad) blew it out with his compressor so dust may have been a problem before, but can no longer take the blame.  I have two fans, one larger than the other but they may still be inadequate.  I usually run with the case closed, but have not put the side back on since new hard drive just because it is still acting so odd.

Thanks for somewhere to look for a start, further suggestions welcome always.

[KatEnigma]

150w?  Wow. Just Wow.

I had more than that on my old machine with the Radeon 7000 in it.

That is definitely one of those scenarios where just having added the new HD would be too much for it, poor thing. 

[J. M. Pescado]

Yeah, a 150W power supply would explain why your computer doesn't work, seeing as I don't think that's enough to even operate the video card, much less the computer.

[Rose Outlaw]

Replacing the power supply might look like a though job, but it's actually rather easy.

The key is to document any move you make and which cable connects to which component. Then make a plan with your new power supply and get a good  screwdriver.

[cassblonde]

I will fourth the power supply. I had something very similar happen to me not long ago on my older computer and got the power supply replaced and had no trouble after that.

Cass

[B]

Replacing the power supply might look like a though job, but it's actually rather easy.

Although replacing the supply is a breeze, finding a good PSU might not be so simple.  Make sure to do your homework before buying, since the cheap solution is not always the best solution. 

[Rose Outlaw]

What would you recommend as important facts of a new supply?
When my old computer's one was replaced by a LC Power Silent Giant 420w, criterias included:

- of course, how many watts? 350w should be the minimun, 450w is far better and anything above 500w is probably pure luxus for an older computer from my POV. But compare the prices. If you can get a 500w+ one for just little more money than a 450w, get the better one. 

- the size of the fan ... my computer case had pretty poor cooling fans, after adding a power supply with a 140mm fan temperatures decreased by 10°C. Also pay attention to reports if the fan tends to break pretty easily or any other common problems.

- are there enough cables to connect all your hardware? Though it's rather unlikely that your 150w one has more than a new one...   

- some may find it important, I did not care for sound or energy cost. Some are more economically, some aren't ... whatever.

[B]

What would you recommend as important facts of a new supply?

An important spec most folks overlook is the 12V amperage.  I've seen 800W PSUs that can't run an 8800GTX because they only provide 24A on the dual 12V rails.  Other considerations:

• P1 Connector - ATX is pretty standard, but you need to make sure it's got a standard mapping.
• Modular or not - If you have a Micro case, modular supplies can ease cable management.  If your case is at least a mid tower, avoid modular.
• Efficiency - Although not everyone thinks it's important, I like to get at least 80%, just cause it saves money.
• Size - Will it fit your case?
• Life expectancy - You want at least 80,000 hours.  If you get a good supply with 10K+, it can always be transplanted to a new machine down the road.
• SATA vs Molex connectors - Most good supplies come with a few of each, but you'll want check just to be safe.

I may have missed something, but this should be a good start. 

[bekka]

Thank you all.  I was looking last night online for a power supply and had no idea what to look for.  Your advice will be very helpful in making the ultimate choice.

[neriana]

When I needed to get my power supply replaced a couple years ago, I went to a local PC repair person. He only charged me what he paid for the power supply, plus $15 for his time. It turned out to be quite a bit cheaper than if I'd done it myself, not to mention easier. Do-it-yourself isn't always the best way.

[bekka]

I completely wish I lived where you do.  Last time I went to my local repair guy it cost me almost $200 to have him tell me that Windoze was corrupted and to reinstall it.  This time I have to go the DIY way or I won't be able to feed my family.  What a difference a few months makes eh?

[B]

I completely wish I lived where you do.  Last time I went to my local repair guy it cost me almost $200 to have him tell me that Windoze was corrupted and to reinstall it.  This time I have to go the DIY way or I won't be able to feed my family.  What a difference a few months makes eh?

Once you have settled on a PSU, the installation is truly a breeze.  You'll only have approximately 6 connectors to deal with, and then you're good to go.  As I mentioned before, finding a decent supply can be tricky, but if you do some homework everything should turn out okay.

[Hegelian]

If the rest of the PC is fairly old (more than 12-18 months) you may have some difficulty finding a PSU that has the proper connector for your motherboard. For some years the standard was a 20-pin connector, but now all the new motherboards and PSUs come with a 24-pin connector (in addition the 4-pin connector that powers the CPU). So you may need to shop around to find a suitable unit (I'm in the same position myself, actually).

As someone mentioned, it isn't just watts; the amps are important also. I've read recently that you need an absolute minimum of 17 amps on the +3.3v rail, and realistically you should be looking for a minimum of 25~30 amps on the +3.3v line and 30~40 amps on the +5v and +12v lines (excuse me if my EE terminology isn't correct).

Also, try to get something with an efficiency rating of at least 70% at 100% load, and with voltage regulation no worse than 5% on the +3.3v, +5v, and +12v rails, and no worse than 10% on -5v and -12v—3% and 5% would be preferable. In essence, you're looking for something like this or better:

Efficiency:   74%
Output:
+5V @ 32A
+12V @ 26A
-12V @ 0.8A
+3.3V @ 28A
+5VSB @ 2A
continuous = 470W / peak = 520W
Regulation:    5% (+3.3, +5, +12) / 10% (-12)
Ripple:    1% (p-p)
Hold Time:    16ms
PG Delay:    300ms
Silencer 470 ATX

Companies that have been putting out good-quality units recently include, Cooler Master, Silverstone, and PC Power & Cooling. The Antec units are popular but have disappointing specs and some users report premature failure, so I would look elsewhere. You can compare specifications and user experiences at Newegg.com.

NOTE:  If this is a Dell PC, there is a good possibility you won't be able to use an off-the-shelf replacement power supply, because Dell motherboards often have non-standard pin-outs on the motherboard connector. PC Power & Cooling offers PSUs specifically for Dell PCs.

[bekka]

Thanks Hegelian, I used your specs when shopping and think I got one that won't make things worse at least.  Not cheap, not expensive and has the ability to use either 20 or 24 pin connector.  So all I have to do now is get over my fear of simple tools and put it in.  Not a Dell thankfully but I've never look closely at my case and PS so that's the next step I suppose. 

[B]

So all I have to do now is get over my fear of simple tools and put it in.  Not a Dell thankfully but I've never look closely at my case and PS so that's the next step I suppose. 

The only tool you need is a Phillips head screwdriver.  Before unplugging the old supply, it might be wise to take a picture or two of the connections so you can always revert to the current setup if you get confused.  Other than that, it's just a plug and play scavenger hunt. 

[KatEnigma]

One piece of practical advice- as you're taking out the last screw, make sure to support the PSU so that it doesn't go crashing onto your cards. 

[witch]

You could probably find a pictorial tutorial on the net, I found one for someone once who wanted to change their video card.

[Hegelian]

I ended up choosing the Corsair VX450w high-efficiency unit for Reggikko's PC. It's a new model on the market, built by Seasonic, a brand well-regarded in Europe. Although new, it is getting quite favorable reviews from sites that do proper, thorough testing with a gaggle of specialized test equipment. The specifications are good, especially for efficiency, although not quite a match for the PC Power & Cooling unit is it replacing. This is the first non-PCP&C power supply I've bought, but the current model (Silencer 470 ATX) is not as well-spec'ed as the one that is being replaced (Silencer 400 ATX); and while a pioneer in the high-quality PSU field, PCP&C seems to be losing some of its edge in the engineering and construction area, at least in its low-end models—the Turbo-Cool 510 ATX in my PC is quite a bit more impressive than either of the Silencers or the Corsair, albeit at more than twice the price:

Turbo-Cool 510 ATX:
+5V @ 40A
+12V @ 34A/38A
-5V @ 0.3A
-12V @ 2A
+3.3V @ 30A
+5VSB @ 3A
continuous = 510W
peak = 650W
Regulation:  1% (+3.3, +5, +12) / 5% (-5, -12)
Ripple:  0.5% (p-p)
Hold Time:  20ms
PG Delay: 300ms

Corsair VX450w:
+5V @ 20A
+12V @ 33A
-12V @ 0.8
+3.3V @ 20A
+5VSB @ 2.5A
regulation unspecified
efficiency up to 85%
active PFC

As a comparison, the Silencer 400 ATX that is being replaced due to start-up problems has these specs:

+5V @ 40A
+12V @ 20A
-5V @ 0.3A
-12V @ 1.0A
+3.3V @ 40A
+5VSB @ 2.0A
continuous = 400W
peak = 450W
Regulation: 3% (+3.3, +5, +12)

If I had gone ahead and tried to fix this problem last year when I bought the motherboard I installed earlier this week (thinking that was the source of the problem), the Silencer 400 ATX would have still been under warranty.   

Oh yeah, now I need to buy a new UPS to replace the 14-year-old APC Back-UPS 400 it's been running on.

[bekka]

All fixed.  I didn't break anything while changing it but had to have help putting is back in as it kept pulling away from the screws.  I managed to get The Sims installed and played for a bit without any problems. 

Thanks so much to all of you for the help.  I'm not afraid to admit I would have been lost without you all.   

[Rose Outlaw]

Well done