Uhh..? Computer problem =/

My desktop computer is about 8 years old, 567 Mhz 192MB RAM running Windows XP (although the specs are irrelevant to the problem). About 2 weeks a go, I left my desktop to idle as I used my laptop right next to it (a great waste of electricity..but I wanted to use AIM while FEAR loaded :p) and suddenly..it shut down.

Naturally, I went to power it back up thinking it might've over-heated and shut down since the fans are pretty old but I've changed the processor fan once and the fan on front seems to be really good since it's still working. However, it didnt boot up, so I switch into troubleshooting mode and first I check whether the surge was overloaded, the reset switch wasnt out so I move on and connect the cord to another part of my surge, that didn't work so I connected it directly to two different wall plugs, that didn't work.

I opened up the computer and noticed that the light on my MoBo that indicated that it is receiving electrical current wasn't on. My conclusion, as many others would've probably been, was that the PSU was gone (for the second time in 8 years) so I bought a 450 Watt PSU that supports SATA and says ATX Switching Power supply (I have a mini-ATX mobo..idk if that will be a problem although I doubt it).

I had the PSU tested at the store because I couldn't return it because it's an electrical component (bleh..). The test was only supported when I connected the PSU to the wall at home and the cooling fan in the PSU did a single spin showing that it is receiving current. But still, the MoBo light wasn't powering on and turning it on obviously didn't work.

At this point I'm tempted to say that it is the MoBo but I don't want to buy such an expensive piece and find out that that's not the problem either (that and money is an issue at the moment since I need to get this problem resolved before I leave to college again). So my simple questions are:

A.) Is there anyway to test whether or not the motherboard is working without any extra tools or extra computers.

B.) If not the motherboard or PSU what else could it possibly be? I'm stumped.



P.S. Sorry for the long post :p Wanted to provide as many details as possible to get the most accurate replies.

UPDATE: In a bad mood, I decided to pre-occupy my mind with attempting to fix the computer again. I decided to unplug all the other power cords besides the main connector (HD, DVD-RW Drive, Fans) and connect that in hopes that for some odd reason that would work. I also decided to connect it to an extension cord I had since I was too lazy to free up my surge protector.

When I connect it, immediately the PSU fan turns on as before except this time it doesnt stop. Then I look down and see the MoBo light turn on but just as fast, it turned right back off and the PSU shuts off. :-/ I try again to connect my PSU and turn it on and off and now the PSU fan doesn't even attempt to spin. I switch out the cord with 2 others I had laying around and that wasn't it either. As I'm typing this I've come up with two new possible problems:

A.) Loose soldering somewhere? Or broken MoBo (Although I saw no visible broken pieces upon quick visual inspection under heavy light)

B.) This isn't a problem but an explanation as to why the fan on the PSU might've turned on earlier re-enforcing point A: possibly the PSU fan turned because it was sending current to the MoBo briefly and the light didn't turn on because it does have a one second delay.

Help is greatly appreciated :)

Hi there Raion, and a Happy New Year :drink:

I don't like the sound of what you are describing. My first thought is that the new PSU is defective. With a desktop PSU the fan should spin continuously, as soon as you supply power. There might be those that don't, but I have never come across one in all my years :confused:

I think that the replacement PSU is defective.

Yeah, sounds like a semi-bad problem, and I'm holding the MoBo suspect, as well. I've had several PSU's go out recent that took the MB with them, and that sounds like what's happened here. Look at it this way : gives you the perfect excuse to build yourself a new computer :)

Micro-ATX mobo's will only tolerate 300W (at most) from the PSU. I know you said "mini-ATX", but I've never heard of that form factor.

I run a Micro-ATX mobo, and the biggest safe power supply that I have found (and am using) runs at 275W.

The mobo may be detecting an overload from the PSU and shutting down to protect itself after you push the power button. That would explain the brief powerup and immediate shutdown.

O

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I think that the replacement PSU is defective.

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Well, the thing is we tested it at the store and it worked fine. He connected the PSU to the AC outlet and connected a metal wire to two specific pins which turned the fan out.

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gives you the perfect excuse to build yourself a new computer

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lol it wont even be my computer, I have my sexy lil laptop which is convenient for my traveling :p

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Micro-ATX mobo's will only tolerate 300W (at most) from the PSU. I know you said "mini-ATX", but I've never heard of that form factor.

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Yeah, Micro is what I meant, sorry. But that is interesting, I'd have to look up on that because I think my old PSU, which lasted about 6 years, is more than 300W but I'd have to update you on that when I get back from work.

Also, I'm going to give it another go when I get home from work and try to run it again..

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I've had several PSU's go out recent that took the MB with them, and that sounds like what's happened here.

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Unfortunately that seems to be quite a common occurrence in my experience as well.

I am not sure about Micro ATX and power supplies. AFAIK power supply is "demand activated" so if you attach a 500w supply it doesn't fire that at the MoBo, it only supplies what the MoBo and drives draw? The 500w value is the theoretical maximum.

OK I suppose you could fry something if you overloaded the MoBo, but with Micro ATX you shouldn't be able to attach sufficient devices as expansion capabilities are very limited.

Either the motherboard is bad, or one of the devices connected
to it is bad and drawing too much current. Any short circuit will
cause the power supply to shut off. I've seen computers completely
dead because of a bad hard drive. If you have disconnected everything,
including cards, and it still won't power up, it's safe to say it is
the motherboard. It doesn't owe you anything, and is too
old to replace with something similar. You're better off
setting it aside to rob parts from.

I also vote that the power supply won't overload the motherboard,
no matter how high it is rated.

This just gets weirder and weirder...

I removed all three PCI cards leaving only the processor and the RAM on the MoBo. When I connected the computer, the MoBo light immediately turned on and remained a bright red. I tried to power it on however, and it didn't turn on.

Next, I turned the PSU off via it's switch in the back, and turned it back on to find the MoBo light still on but dimmer than before. I repeated again and it got a bit dimmer (to the point where I had to cast a shadow over it to see it). Then I spoke on the phone with my brother attempting to get his analysis of the problem and he was just as baffled as I was. When I got off the phone, I tried again and the light turned BRIGHT red for about half a second then turned off but powered back on in it's dim state a few seconds later.

Now I'm in the process of opening the manual and checking the cables which signal the computer to turn on however I highly doubt that is the problem.

Which would be the most probable cause of the problem that needs to be replaced? This is really stressing me out and I honestly don't have the time to be harassed by my parents about this any further.

EDIT:

I figured out why the light turns BRIGHT red when it does. It always turns bright red first when the power button is suppressed before turning the power supply on.

BTW, My old PSU is 300W

Well,

At this point I guess I would take out the MoBo, put it on an insulated mat and run it outside of the case. That would eliminate the short circuit issue?

I am also starting to wonder about the processor?

As was mentioned by delstar, when a PSU goes South you never know what collateral damage has been caused?

:(

This may seem like a stupid question but I'll ask anyway...

A micro ATX will only handle a 300 watt power supply?

The load decides the power demand not the source. The power supply rating is the maximum sustained load the power supply can provide. You could put a 1000 watt power supply on there and nothing's going to happen unless you short something, then you could arc-weld.

Hi dddc, belated Happy New Year, I hope you and yours are all well.

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The load decides the power demand not the source. The power supply rating is the maximum sustained load the power supply can provide. You could put a 1000 watt power supply on there and nothing's going to happen unless you short something, then you could arc-weld.

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I agree entirely, except that I would prefer 3000w for arc-welding:zap:

I think the confusion might be that it is pretty difficult to find a PSU in micro ATX format that is more than 300w. I think the reason for that is that the form factor doesn't support expansion that would require more, so manufacturers don't make them?

EDIT:

And another thing, slightly off topic:

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My desktop computer is about 8 years old, 567 Mhz 192MB RAM running Windows XP

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Not good IMO. A machine of that age will be using PC133 SDR at best. :(

Yeh...I began to suspect the processor myself but there is absolutely no way of pinpointing what the problem is exactly anymore :-/ If I have to buy a processor I might as well re-build it with a faster one (and a socket better than 370) and a new MoBo.

What I will probably end up doing is buying a new MoBo and pray to god that is the problem.

BTW, yeah, I was very hesitant to switch to XP. So much so that I had Windows 98 for about 1-2 years after XP was out then switched to 2000 Professional for about a year until one day I connected my friends hard drive to my computer (with XP) and it ran smoothly so I upgraded. However, that computer isn't used for anything too strenuous. The most I did on it was Photoshop when I used it, when/if I fix it it'll be used to word processing mostly.

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Originally Posted by Raion

Yeh...I began to suspect the processor myself but there is absolutely no way of pinpointing what the problem is exactly anymore :-/ If I have to buy a processor I might as well re-build it with a faster one (and a socket better than 370) and a new MoBo.

What I will probably end up doing is buying a new MoBo and pray to god that is the problem.

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If you are looking at a socket478, I'm your man!

O

Ugh.

So I gave up on the computer due to a lack of time, took it to a computer repair shop and they concluded the same as we, that the MoBo needed to be replaced. Again, I didn't have time to do this so I bought a new desktop all together for ~$125 without a hard drive. The specs are fine for what my little sister will do on it.

But now I'm just frustrated still since I can't change the bootorder. For some reason it doesn't bypass the preceding devices (CD-ROM, Floppy, USB) and doesn't boot. When I go to the BIOS screen and go to Boot order there is literally no possible way to change it. I've pressed every possible key. Suggestions, ideas?

BTW, I booted Knoppix live CD, and it worked perfectly (as CD-Rom is the first in the boot order). I did this to make sure I connected the hard drive properly and it was being read properly as well. Which it is.

I also disconnected all USB devices to make sure that wasn't it...nothing. It simple stays at a black screen with a blinking underscore.


EDIT:
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Okay. I reset the CMOS battery and was able to reconfigure the boot order successfully (and the changes are saved) but I still get the same black screen with the blinking underscore......I'm CONFUSED.

The BIOS does detect the HD correctly so I didn't connect the IDE cable the wrong way...

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Originally Posted by Raion

EDIT:
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Okay. I reset the CMOS battery and was able to reconfigure the boot order successfully (and the changes are saved) but I still get the same black screen with the blinking underscore......I'm CONFUSED.

The BIOS does detect the HD correctly so I didn't connect the IDE cable the wrong way...

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Hmm...first of all what it the make/model of the MOBO, and what BIOS is it using? The only thing that I can think of is that the CMOS battery is dead, and is working like a TV remote control when you open up the casing and give the batteries a twist...it'll work for a few more clicks, but no more than a few. Does it get through all of the bootstrap (configuration, mem checks, etc.) and then freeze up at the blinker?

I'm leaning towards a dead CMOS battery. Not a huge deal, really.

O

Well, FINALLY.

Apparently the switch to the new MoBo corrupted Windows (??) and I reformatted and all is well now.

Thanks all :)

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when a PSU goes South you never know what collateral damage has been caused?

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my DAD switched th ePSU 240 / 110 v switch across whilst PC was running [I don't know why :p] and the collateral damage was as follows

all I could recover was the feckin CASE :eek:

cpu / RAM / Mo-Bo / HDD's even the DVD ROM went west
so if your PSU faulted, it would send a fault load down into your PC, so even when you fit a new PSU, the original fault has still fried possibly everything after the PSU

there are tests to prove each item
but it is generally safer to assume total loss
and hope your backups were up to date ...................

luck to you