PC Will not power on

[Jesse Torres]

Last night while browsing the internet, my PC turned off for no apparent reason. I then tried to turn it back on to no avail. The computer will not even power on. I opened the case and again pressed the power button. The fans inside spun for about a second and then turned off. What is strange is that the motherboard light stays on.

Thinking that it was maybe the power supply, I bought a new one today. Unfortunately, the computer will still not power on. As I mentioned, the fans spin for probably a split second and the motherboard light stays on.

I checked all the connections and everything seems fine.

I found a site that gives advice on computers that will not power on. It states the following.

Check the power switch on the PC's case and make sure it's properly connected to the motherboard. Try shorting the jumper pins that the switch uses to power on the PC. If that works, the switch is bad.
I absolutely have no idea what that paragraph means.

Any suggestions or advice are greatly appreciated.

Thanks,

sus

[Alan Ford]

Only things I can think of is:
1 CPU fried (higher posibility) 90%
2 memory fried (lover posibility) 50%
3 motherboard fried (lovest posibility) 5%

Did you feel any smell?

I am sure that hd is ok.

[Jesse Torres]

Originally posted by Alan Ford:
Only things I can think of is:
1 CPU fried (higher posibility) 90%
2 memory fried (lover posibility) 50%
3 motherboard fried (lovest posibility) 5%

Did you feel any smell?

I am sure that hd is ok.

Thanks for your help. If Mo-board were fried, would the mo-board light remain lit? Also, how can I tell if CPU is fried?

Thanks so much,

[Lasse Koskela]

Originally posted by Jesse Torres:
Thanks for your help. If Mo-board were fried, would the mo-board light remain lit? Also, how can I tell if CPU is fried?

Open the box and smell/look at it. You'll know if it's fried...

[Jesse Torres]

Originally posted by Lasse Koskela:

Open the box and smell/look at it. You'll know if it's fried...

Thanks for your response. The mo-board doesn't smell. In fact, it doesn't have any burned spots. If I press the power, the CPU fan spins for a split second and then stops. So, the computer never boots. However, the Mo-board light remains lit. I already put in a new power supply.

Any help will be greatly appreciated.

Thanks,

[Helen Thomas]

How can you tell if it isn't a virus ?

[David O'Meara]

Have you moved or knocked the box? Based on the start-up behaviour and my rudimentary hardware knowledge, it doesn't sound like it's getting up to the BIOS startup. This is before the memory or harddrive get involved, so less likely to be them.

From what I remember of the first few seconds of power up, you get something like this:
1) turn on the power
2) fans turn on (check)
3) BIOS starts and performs some simple checks.
*) Where does the video card check occur? wouldn't this be before BIOS? I wonder what would happen if the video card was dead and failed its startup test? You wouldn't see anything (cos it doesn't work!) and you may not hear anything either. I need to go to my BIOS book and see if there's a beep code for this.

I'm also assuming you don't hear any beeps during startup? Usually a set of short and long beeps.

[David O'Meara]

Sorry, I was asking if you moved or knocked the box since I was wondering if you may have reset the BIOS, but then I remembered it's in flash memory with a battery backup for changes. If you'd bumped it, it would have reset to factory default settings.

[Andrew Eccleston]

Originally posted by David O'Meara:
I wonder what would happen if the video card was dead and failed its startup test? You wouldn't see anything (cos it doesn't work!) and you may not hear anything either. I need to go to my BIOS book and see if there's a beep code for this.

Generally speaking, if the video fails, the board will give a beep code. Like you said, David, you wouldn't see anything, so an auditory warning seams pretty standard. (At least it has been on the last several boards I've used) I seem to recall that being the case with memory, also, but I can't say for sure. Although, when I've seen those particular cases before, the board would maintain power until you turned it off.

Jesse, I personally wouldn't worry about the power switch itself anymore. Since you get power for second (when the fans spin), the switch seems to be doing its job. I think I would try to test the CPU and RAM in a different machine, if possible. Admittedly, there is a little bit of a risk there, but it's probably your easiest way to identify the bad part.

One thing you could try:

Try booting with only the CPU, RAM, video card, keyboard and mouse installed. Remove everything else that you can. If this configuration boots (you don't need to go all the way to the OS boot, just to the BIOS checks) start adding one component at a time until you find the component that fails.

I would suspect either the CPU, or the BIOS chip. But, it's really hard to diagnose when I don't have my hands on it.

Best of luck!
[ October 22, 2004: Message edited by: Andrew Eccleston ]

[Jesse Torres]

Originally posted by Helen Thomas:
How can you tell if it isn't a virus ?

I absolutely don't know since the PC will not even boot.

[Jesse Torres]

Originally posted by Andrew Eccleston:




One thing you could try:

Try booting with only the CPU, RAM, video card, keyboard and mouse installed. Remove everything else that you can. If this configuration boots (you don't need to go all the way to the OS boot, just to the BIOS checks) start adding one component at a time until you find the component that fails.

I would suspect either the CPU, or the BIOS chip. But, it's really hard to diagnose when I don't have my hands on it.

Best of luck!

[ October 22, 2004: Message edited by: Andrew Eccleston ]

I removed everything and only booted with the CPU, RAM, and Video Card. Unfortunately, nothing occurred. The CPU fan and the other internal fans once again spun for a split second, maybe a millisecond. During that split second, the Motherboard light lit. It indefinitely remains lit.

I then removed the Video Card and only booted with the CPU and Ram. Same end result. The computer is not even emitting any beep codes.

I have already cleared out the CMOS settings by removing the CMOS battery and specifically putting a jumper in the CMOS clear pins.

What exactly is the BIOS chip?

Thank you all for all of your help,

[Andrew Eccleston]

The BIOS chip is what stores the actual BIOS/CMOS code.

More specifically, it has "flash RAM". When you "flash" or update the BIOS on your motherboard, you basically overwrite the flash RAM with a newer version of the code.

Sometimes these chips fail, and if so, you can get some pretty varied results. It may be the BIOS chip, but it could be something else on the board. Maybe even the CPU. The fact that you didn't get any beep codes with the video card removed has me leaning toward a motherboard issue.

Any chance you can test the CPU, RAM, and video in another machine?

[Jesse Torres]

Originally posted by Andrew Eccleston:
The BIOS chip is what stores the actual BIOS/CMOS code.

More specifically, it has "flash RAM". When you "flash" or update the BIOS on your motherboard, you basically overwrite the flash RAM with a newer version of the code.

Sometimes these chips fail, and if so, you can get some pretty varied results. It may be the BIOS chip, but it could be something else on the board. Maybe even the CPU. The fact that you didn't get any beep codes with the video card removed has me leaning toward a motherboard issue.

Any chance you can test the CPU, RAM, and video in another machine?

I can't test the CPU or even the RAM on another computer. The motherboard only supports DDR RAM and AMD Chips. I have another PC but it has a Motherboard that supports only Intel Pentium chips.

The computer is not emitting any beep codes, even if booting without a video card. This is extremely odd. It only stays on for a millisecond. So the fans don't even make a 360 Degree turn. Instead they probably only make a 180 Degree turn. What is funny is that the motherboard light remains lit.

I am going to Radio Shack right now to purchase a new CMOS battery.

Thanks,

[Andrew Eccleston]

The CMOS battery, AFAIK, is only used while your pc is off in order to retain your CMOS settings and system time. If your battery were dead, you should just lose your settings, and have to go through CMOS each time you boot. Since you're not getting that far, I doubt that the batter is the problem.


Based on your above response, can I assume that you don't have another MB
that you could try? What about a friend with a compatable MB, perhaps that you could drop your CPU, RAM, and video card into?

[Jesse Torres]

Originally posted by Andrew Eccleston:

Based on your above response, can I assume that you don't have another MB
that you could try? What about a friend with a compatable MB, perhaps that you could drop your CPU, RAM, and video card into?

All my friends and family members have Dell PCs with Motherboards that only support Intel Pentium CPU.

I guess I will purchase a new PC. The mo-board + CPU will cost from $200 to $300. I am afraid that the mo-board and/or CPU might once again fail. As a result, I might as well purchase a low end Dell with a flat panel monitor for $449. That includes free shipping, free upgrade to flat panel, and 6 months of free internet.
[ October 22, 2004: Message edited by: Jesse Torres ]

[Andrew Eccleston]

Well, that's one option, and certainly your choice. My gut feeling is that it's your motherboard that's bad. In which case, you could probably replace it for under $100, and keep the rest of your hardware.

Of course, with the price you mentioned, and the free flat-panel upgrade, you've even got me tempted to buy a Dell!