Computer Help forum


PC cannot turn on

by Moraja / July 3, 2011 4:20 AM PDT

I have a 2 yrs old, home built system with the following:

- OS: Windows 7 premium edition, 64 bit
- Processor: AMD 2.10 gigahertz, Phenom 8400, x3 core
- Hard drive: 200 gigabytes
- Motherboard: ECS GF8100VM-M5
- Memory: 2MB + 1 MB
- Display: Nvidia GeForce 8100 / nForce 720a

The pc was built by someone else, so I don't know much about it. It worked fine until a few weeks ago when it started switching off without any error messages or warnings - just as if someone pulled the plug (and I haven't). I would just turn it back on again. It only did this while gaming. It also started to lag. I ran anti-virus, but it found nothing. Defragmenting the drive helped it run slightly faster, but it still wasn't its old self.
Then, a few days ago it switched off and would not turn on again. Only the fan lights blinked and nothing else.
I thought it had something to do with power supply and bought a new box.
It didn't help and it only turned the fans on for a moment, just like the old one. So, I put the old one back in and looked up the forums.
I plugged in one cable at the time and found that everything works until the ATX 12v connector cable is plugged in. As I understand, this connects the CPU.
I also read somewhere that the motherboard is supposed to beep when powered. I am not sure if my one ever did this, but it makes no sound now.

- Does this mean that it needs a new CPU?
- Motherboard has a fan that is powered through it and it works. Is it possible that the motherboard is still faulty in some other way that allows the fan to work?
- Maybe it needs both, motherboard and CPU?

Any help to solving this is much appreciated.


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All Answers

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Your stated symptoms are typical of ...
by Edward ODaniel / July 3, 2011 5:40 AM PDT
In reply to: PC cannot turn on


It could be that your processor has been overheated too many times and has failed but it could also be that the heat sink compound between the processor and the heat sink needs replacing. Try that first as it is a cheap fix if it works.

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I'll try that...
by Moraja / July 3, 2011 6:19 AM PDT

Thank you for your answer, I'll get some compound first thing tomorrow and try changing it.

The PC has a total of 4 fans so I didn't think it may overheat. Maybe I should fit one more once it's fixed...

I'll post here with the results.

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Changed the compound...
by Moraja / July 3, 2011 10:50 PM PDT
In reply to: I'll try that...

I have changed the compound, but the problem persists.

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Tell a little more.
by R. Proffitt Forum moderator / July 3, 2011 7:08 AM PDT
In reply to: PC cannot turn on

1. Did you inspect for BAD CAPS? (see google)

2. What size power supply?

3. Did you test the power supply? (see google. example TEST PC POWER SUPPLY GREEN WIRE)

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I have tried:
by Moraja / July 3, 2011 10:58 PM PDT
In reply to: Tell a little more.

1. I have closely inspected the mb and all capacitors appear in good condition

2. The power supply is 300W

3. The power supply was tested and it works. I have also tried a new one and got the same result.

I have so far established that it is the ATX 12v connector that is causing the problem, because when that one is plugged in, nothing works. Without it, all the fans run, decorative lights come on, and I can hear the hard drive starting up as well.

What does it mean?

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That's bad news.
by R. Proffitt Forum moderator / July 4, 2011 5:13 AM PDT
In reply to: I have tried:

If it won't power up with the AT12V that's usually a sign of overcurrent on that leg. Can be caused by an EXTRA mounting stud on the backside of the motherboard that doesn't belong to IDE cables upside down.

The first I have to pull the motherboard, the second I just unplug the IDE cables.

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I thought so...
by Moraja / July 4, 2011 7:31 AM PDT
In reply to: That's bad news.

No change with IDE cables unplugged.

The pc worked for nearly 2 years before this without any alterations. Wouldn't this have come up when it was first built, if the stud is causing the overcurrent?

Kind regards,

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I can explain that.
by R. Proffitt Forum moderator / July 5, 2011 12:11 AM PDT
In reply to: I thought so...

Having found this too many times and the owner writing or yelling it worked for years and it can't be that... the stud was an extra and the paint on the motherboard finally wore through.

I'm sorry but I have to ask. Is every idea I give going to have to be re-told? The issues are easy to check out and we would be moving in slow motion if an idea too many posts and replies.

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Yellow stains
by Moraja / July 5, 2011 9:33 PM PDT
In reply to: I can explain that.

I found six studs, but don't know which one is extra as they were all used.

However, the back of the motherboard has yellow stains that look like leakage.
Bad caps after all?

I am guessing that I'll need a new motherboard?

P.S. The question in my previous post is because I just want to understand. What seems easy to you is a mystery to me.


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by R. Proffitt Forum moderator / July 6, 2011 8:24 AM PDT
In reply to: Yellow stains

That's a common leak I found on some BAD CAPS. You can learn more about this on google and BAD CAPS.

Then again, did anyone spill liquid anything on that machine?

Motherboards are rarely repaired with a fine exception being BAD CAPS.

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by Moraja / July 6, 2011 7:41 PM PDT
In reply to: GOOD FIND.

There were definitely no liquids spilled. Could it have been a victim of overheating?

I couldn't find the right capacitors, and the liquid looks like it soaked through the board. I'll attempt to repair it in the future for another pc - if possible, but for now I need to fix this asap.

I ordered the following replacement:

GIGABYTE GA-M68M-S2P GeForce 7025 microATX Motherboard - AM3/AM2+/AM2 Sockets

Do you think it will be compatible with the above specifications?


P.S. Thank you for pointing me in the right direction

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I can't tell.
by R. Proffitt Forum moderator / July 7, 2011 2:23 AM PDT
In reply to: Replacement

Sorry but a quick look didn't find the answer. REMEMBER THIS IS ALL VOLUNTEER and if I have to dig up web pages or GUESS WHICH CPU then I give up fast.

Try this.

Head to your new motherboard spec page and see if the CPU is on the list.

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I did not expect you to comb the net
by Moraja / July 7, 2011 3:22 AM PDT
In reply to: I can't tell.

Fair enough if a quick look didn't provide the answer, and I have clearly expressed my appreciation for your time in previous posts.

CPU is specified in my first post, so there was no need for you to guess, but never mind.

Looking through your posts, you evidently have the knowledge, but seem to find the questions annoying. REMEMBER: if we knew we wouldn't be asking!



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I found a few variations on the CPU.
by R. Proffitt Forum moderator / July 7, 2011 3:47 AM PDT

So I couldn't tell which one it was and there were revisions on the motherboards.

All I could think of was to supply you with how to tell if it was on the list.

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What specs to go buy?
by Moraja / July 7, 2011 4:45 AM PDT

I only have the basic understanding of hardware, and find it difficult to choose as the list of specifications makes my head spin!

I looked at the following:

- Support for AM2+ socket
- Support for Phenom
- Chipset:
NVIDIA GeForce 7025/nForce 630a

- AM2+ Phenom HT3.0 (says next to the CPU)
- Phenom x3 core, 2.1 GHz CPU
- Chipset: Nvidia GeForce 8100 / nForce 720a

If you need any other parameters, let me know. Please do not feel that you should search for anything on the net - more than anything I need pointers, I'll do the searching and post here.


P.S. It also says this:

"If you install AMD AM3/ AM2+ CPU on AM2 motherboard, the system bus
speed will downgrade from HT3.0 (5200MT/s) to HT1.0 (2000 MT/s) spec;
however, the frequency of AM3/ AM2+ CPU will not be impacted."

Does this mean it will be slow?

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Should be fine.
by R. Proffitt Forum moderator / July 7, 2011 5:59 AM PDT
In reply to: PC cannot turn on

I have had too many AMD systems over the years and that number doesn't seem to matter too much.


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Windows cannot start
by Moraja / July 8, 2011 6:36 AM PDT
In reply to: Should be fine.

- Confirmed competability on manufacturer's site (motherboard/CPU)
- Used new PSU (as the atx12v connector had stains from the leak - did not want to risk it wth my shining new mobo)


Then Windows would not start Cry

Does this always happen? Is reinstallation of Windows 7 my only option? I only have an upgrade version.


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Re: Windows can not start
by Kees_B Forum moderator / July 8, 2011 6:41 AM PDT
In reply to: Windows cannot start

With a new motherboard a reinstallation of the OS is often required. It might be the upgrade version still can be used. If not, go back to what you had before you upgraded and upgrade again. That costs a lot of time. But buying a new license costs a lot of money. Your choice.


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Posting this from a fully repaired PC
by Moraja / July 10, 2011 5:52 AM PDT

I had to do a full install instead of an upgrade, which would have saved my files and settings.

On the bright side, it only took only about half an hour and all my data was saved in 'windows.old' file. I was able to do this using my Windows 7 upgrade CD, so there was no need to install XP or buy a new licence.
From what I gather, the upgrade CD actually has the full OS.

THANK YOU ALL FOR YOUR HELP AND TIME - before this happened I have never done more than change a DVD drive - and I can hardly believe I fixed it myself Grin

Best wishes,

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RE: "Then Windows would not start" ...
by Edward ODaniel / July 10, 2011 5:48 AM PDT
In reply to: Windows cannot start

What exactly did happen and how long did you wait?

With some motherboard changes when you boot the first time it appears to just hang and the mouse and keyboard do not respond - wait quite a while before telling yourself that Windows isn't starting as it migh just be catalogginf the new hardware of the motherboard. If this is the case it will eventually indicate this and you need to reboot and install the new motherboard drivers and you are off to the races.

On many other motherboard changes there are enough differences that Windows simply does not start but you should be able to perform a repair install where you install Windows over itself and then after the repair installation you still need to install all the new Motherboard drivers.

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by Moraja / July 10, 2011 7:53 AM PDT

I have changed the motherboard from: : ECS GF8100VM-M5 to: GIGABYTE GA-M68M-S2P

When I first turned on the system, after putting everything back together, it powered, then a screen came up 'automatic startup repair'.

-The mouse and keyboard worked
- Automatic windows startup repair attempted to repair, but was unable to
- There was a choice to shut down, or more options: Restart (tried), System Restore (tried), Repair from system picture (didn't have it), Command prompt (didn't have a slightest idea)
- Tried to repair it from the W7 installation disk - unsuccessfully
- Tried to install drivers from W7 installation disk, but it asked to choose files and I didn't know which one

I tried all the options I could think of before finally giving up and doing a full installation.

So, now that's sorted, I'm off to tackle the new problem - where it's saved EVERYTHING in the 'Windows.old' folder it's taking up a considerable portion of my hard drive. Some folders refuse to be deleted...

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