[spacesurfer]

My old computer that I built has a ASUS P5GDC-V mobo and a Pentium 4 3.0 Ghz processor.

It's not turning on anymore. When I open the case, I see that the green light is on inside. But it just won't turn on at all - no POST, no DVD/CD drive lights come on like they usually do when first turning on.

So, question is:

1) Could it be that my PSU needs replacement? I've been having a HDD problem in that one as well - it crapped out a couple of times - would not getting power to HDD cause it to be not detected at times?

2) Would the green light on mean that the PSU works?

3) If the processor is burned out, would the computer turn on at all to POST?

If I can't get it to work, then I think I'm gonna have to shell out some money for a new MOBO + processor and will need help with choosing the right one. I got an okay from my honey-bunny <--- very important!

Thanks.

[Ponch]

1) could be. Tough you could first try to remove every additional card, reset the memory modules and video card (if not onboard) and retry. Also test with memory modules one by one if applicable. A good reset of the board can help sometimes.
2) it proves it's plugged in but not that it's working 100%
3) no. The processor really does it all.
Good luck.

[MCT]

i would say its probly your motherboard, but id take it into your local pc shop, they can hook up testers & stuff so u can have the right diagnosis for a small fee, my local shop charges 15 bucks to do that.. so its not too much

u can remove stuff , like harddrive & videocard, it will post or give a beep saying that those are missing, but it will rule those things out for u

[jcarle]

I put my money on a dead power supply.

[James_A]

From repair experience, the power supply is the most likely culprit. The green light simply shows that the standby power is still available, but that doesn't mean that the PSU will give enough power to start anything up. It's not always the cause, but without any other info it's always the first thing to suspect.

Also don't ignore the battery. Yes, really, that coin-shaped silver object. I've just had a computer in for repair, which failed to do anything at all, checked everything and swapped in-and-out everything. Finally, put the battery in another motherboard and had exactly the same symptoms. That particular battery is like the death-pill to any motherboard. Usually you can tell when the battery is failing -- not this one.

.

[spacesurfer]

Yes, I am suspecting the power supply... if it was failing, it would also cause hard drive problems, wouldn't it if the hard drive didn't receive enough power...

cause I really think there is nothing wrong with my HDD as the SMART report showed everything was okay but it just crapped out twice prob from not enough power.

Also, how long do CMOS batteries usually last? My mobo is 3.5 years old. I've never replaced that battery before. I'll look into that as well.

Thanks.

[puntoMX]

spacesurfer, on Nov 18 2008, 05:41 PM, said:

2) Would the green light on mean that the PSU works?

It ONLY shows that the 5V line of your PSU is "OK".

James_A, on Nov 19 2008, 01:59 AM, said:

That particular battery is like the death-pill to any motherboard. Usually you can tell when the battery is failing -- not this one.

Interesting, I never had that. What motherboard are we talking about here?

spacesurfer, on Nov 19 2008, 12:59 PM, said:

Also, how long do CMOS batteries usually last? My mobo is 3.5 years old. I've never replaced that battery before. I'll look into that as well.

Out of the box it could fail, but I don´t think it´s your problem there...

Like other said, swap out that PSU. Don´t tell us what brand it is .

[spacesurfer]

A good PSU for about $50 USD? I have 2 SATA HDD, 2 CD/DVD (1 IDE and 1 SATA).

I'm thinking 600 watts should be enough. I need at least 3 SATA connectors. I do have converters but would be great if the PSU had at least 2.

What is the diff between 24 pin and 20+4 pin?

I'm looking at this one: http://www.newegg.com/Product/Product.aspx...N82E16817162017

This post has been edited by spacesurfer: 19 November 2008 - 06:55 PM

[puntoMX]

spacesurfer, on Nov 19 2008, 06:05 PM, said:

What is the diff between 24 pin and 20+4 pin?

I'm looking at this one: http://www.newegg.com/Product/Product.aspx...N82E16817162017

Well, if your motherboard has only 20 pins you can only use the 20+4 version, it´s a 24 pin connector where you can take 4 pins off, so to say.

Ahum... that´s a really... really bad PSU...

Check out the Antec earthwatts EA380, 10 bucks more but worth 10 times more.

And cheap if you beleve in MIR: COOLER MASTER eXtreme RP-500-PCAR, 17USD .

[spacesurfer]

I'll need more than 380 watts don't I - with 2 roms and 1 and maybe another HDD?

[puntoMX]

I won´t see why you need more, the 12V lines are the most important these days and a hard disk takes up about max.12W, a DVD-RW not much either.

Do NOT look at the silly model numbers, "600W" or anything like that on a PSU doesn´t say anything (besides marketing crap) .

[Tripredacus]

spacesurfer, on Nov 20 2008, 02:48 PM, said:

I'll need more than 380 watts don't I - with 2 roms and 1 and maybe another HDD?

I am pretty sure that the Pentium 4 (unless newer revisions changed this) requires a 400w PSU. THat's what I had to get for my P4 computer.

[spacesurfer]

I would prefer to make it a bit future-proof - eventually, maybe in a year, i want to replace it with a Core i7.
But since these multi-core processors require less power, wouldn't that mean you don't need high wattage?

[cluberti]

Each core is more efficient, yes - but with 2 and 4 cores on a die, you still need more juice overall.

[puntoMX]

Well I tried, it seems that you 2 (spacesurfer and Tripredacus) are blind to see the difference between a cheap a** 400W PSU (17-19A on ONE 12V line) and a real 380W PSU (TWO times 17A (Lets say 30A combined?) (TWO 12V lines)).

Dig out your pocket and go for a "future proof" PSU: SeaSonic S12 Energy Plus SS-650HT.

That should do the trick .

[spacesurfer]

puntoMX, on Nov 20 2008, 05:28 PM, said:

Well I tried, it seems that you 2 (spacesurfer and Tripredacus) are blind to see the difference between a cheap a** 400W PSU (17-19A on ONE 12V line) and a real 380W PSU (TWO times 17A (Lets say 30A combined?) (TWO 12V lines)).

Dig out your pocket and go for a "future proof" PSU: SeaSonic S12 Energy Plus SS-650HT.

That should do the trick .

Dude, I've built only 3 systems so far and never considered the PSU as a vital component with certain specs to look for. Hence, don't know much about them except the wattage. Would be delighted for education. Anyway, so you are saying that the 380W Antec delivers more than just the 380W as claimed???

The physical lesson in high school on W, Amps, and volts isn't coming back to me.

[puntoMX]

spacesurfer, on Nov 20 2008, 05:47 PM, said:

The physical lesson in high school on W, Amps, and volts isn't coming back to me.

Okay, no problem, let´s go back to the PSU you picked:

The specs look "ok" with:

Output +3.3V@32A,+5V@50A,+12V@24A,-12V@1.0A,+5VSB@2.0A

The +12V is market in red, and the +5V in blue for easy reference.

The 5V+ line is heavily overdone with its 50A, not needed at all, only for a part of the motherboard and some other low level I/O, not even getting close to those 50A even if you try hard . It also resembles a 250W (U*I indeed to use the simple formula). The 3.3V line is probably more used in a modern system than the 5V line; think about PCI / PCI-E cards, chipsets and the Hot swap SATA (105.6W). So, those 2 lines combined will give you the total load, it´s about 60% of the totals, so let´s say 213W. Then we have the most important line, the +12V; 24A so you would say 288W but combining them with the other 2 lines you will get about 60% out of that max., making it a useful 173W. So, when we add up those 180W+230W we´ll have left a lousy 386W of those 600W AND a overdone 5V line with it´s 50A! A loss of more than 30%?; yes, that´s the marketing trick, cheap components to get high numbers and add some "extra" on top of that, not even thinking about how much it pulls away from your power outlet with it´s efficiency of 65% (unless you like to head up the place with it).

Now, with this “knowledge” we look at the Antec earthwatts EA380 I showed you.

Output +3.3V@20A,+5V@20A,+12V1@17A,+12V2@17A,-12V@0.8A, +5VSB@2.5A

hmm, now, that´s looks different in every way; They cut away of the not much needed 5V line and added an extra 12V line to get more power out of cheaper components but still giving about let’s say 28A real Amperes out of those.
So, let´s make the calculation here again:

3.3V at 66W
5.0V at 100W
12V1 at 204W
12V2 at 204W

Subtotal of 574, let´s say 2/3 can be used at max., leaving a REAL 380W.

I hope this clears it up a bit .

[CoffeeFiend]

spacesurfer, on Nov 20 2008, 06:47 PM, said:

never considered the PSU as a vital component with certain specs to look for.

It VERY much is, and not only when it comes to computers! You wouldn't believe how many systems I've seen who didn't work because of that (and again, I don't mean just computers here).

spacesurfer, on Nov 20 2008, 06:47 PM, said:

The physical lesson in high school on W, Amps, and volts isn't coming back to me.

There's just FAR more to it than just "what is wattage":
-you have to have power where it counts/where you need it. That junk PSU has way too many amps on the 5V rail (that screams old outdated design already, i.e. a classic early ATX era design), and not enough where you really want more i.e. the 12V rail(s)
-you have to understand how they're electrically built: often, different rails are powered from the same tap on the same transformer, so they'll claim X amps on a rail and Y amps on another, but both combined cannot exceed what the transformer's output can handle i.e. combined power limits, which are clearly missing on this unit (like on most junk PSUs where they'd rather you not know! more or less lying by omission here)
-a lesson in quality: cheapo PSUs use garbage components overall (everything to save a penny), like crappy capacitors and a lot of other inadequate parts (e.g. diodes & mosfets that cannot handle the advertised load, bolted right onto inadequate heat sinks no less) that will quickly fail
-a lesson in real-life conditions: perhaps they claim it can provide that much power, assuming the heat sink the parts rest on is at 20 degrees Celsius, with similar room temp. Too bad that in real life, the air getting in your PSU will be hotter, and the heat sinks hotter too. And some key components derate with temperature (loose capacity), so the real-life capacity just isn't what they claim (I've plenty of times seen junk PSUs where some parts couldn't handle half the current stated at "normal" operating temperatures)
-a lesson in marketing: wattages on garbage PSUs are often just plain old lies by their marketing department (they probably call it more like "being creative with math"). I've seen generic 600W PSUs die with a 350W load before -- it's not uncommon at all. Most generic PSUs fail WAY below the wattages they claim.

Take some time to read this (and laugh a bit). Then you won't ever consider buying another no-name/generic PSU anymore ever (I hope so anyways). Hint: the very first PSU tested (a 650W junk unit) dies at 184W of load... I wish I could say I'm surprised.

The better companies' products are a million times better. Not only they include good/useful/important features like Active PFC, 80+, better filtering, various optional protections and plenty of other reasons (better connector sets, modular designs, cleaner power, etc), but they can actually supply as much power as stated, in real-life situations (and high temps), where it counts/is needed. They will often pay for themselves, being 80+ and also by outlasting junk no-name units' lifetimes by a long shot.

Garbage PSUs sell very well. Because they're cheap, and most people don't see past the one number (wattage). Just like some people don't see anything else than the clock speed when buying a CPU, or the megapixels when buying a camera. That provides a strong [monetary] incentive for continuing to sell junk unfortunately.

Designing, building, testing and repairing SMPS'es is part of what I do for a living.

This post has been edited by crahak: 20 November 2008 - 09:02 PM

[puntoMX]

Nice add crahak for the people that know a bit more, I just kept it simple .

[CoffeeFiend]

puntoMX, on Nov 20 2008, 10:00 PM, said:

Nice add crahak for the people that know a bit more

Thanks!

puntoMX, on Nov 20 2008, 10:00 PM, said:

I just kept it simple .

Then I guess I tried to... But even then, there's just soooooooo much more to it. Group regulation? Overall assembly quality (e.g. lose screws)? How many 12V rails (and how they're "distributed" on different cables)? Nylon braid on the wires (and the gauge of the said wires)? Ripple? How god/quiet/effective the fan is (brand? sleeve or bearings)? What optional protections are there and how well do they work? Efficiency curves? ... We could go on for just about forever here.

With the nicer PSUs one pays for a lot more than just brand name. There's a GIGANTIC difference in quality too.

puntoMX, on Nov 20 2008, 10:19 PM, said:

EDIT: Why don´t i see you online (MSN) any more crahak, or replies on my PMs .

Lack of time as always! Stuff to do around the house, a last minute near-deadline GDI+ app I gotta work onto, etc. My life is pretty crazy at times. I shouldn't even be "wasting" time posting here!

This post has been edited by crahak: 20 November 2008 - 09:29 PM