CPU Upgrade and a dead PC to show for it...

[JSD7878]

To all:

Ok I was attempting a simple CPU Change out process and now I cannot start my PC at all. I have performed this process a dozen times.

I was upgrading from a AMD 3200+ to a AMD FX55, here's what I know: 1) I know that the motherboard light comes on indicating power, I know that when I plug in device into the USB slots they light up ie my keyboard but when I press the power button to try an turn on the PC nothing lights happens, no fans, nothing starts it's a like a dead box. Furthermore I thought hmm maybe this is a bad CPU I will just reinstall the old one and at least I would have a working PC, well I put the old CPU back in and the same problem, no startup.

I have checked all the connection inside the PC to make sure everything is properly seated. I made sure to check that none of the wires were accidently pulled off their pins during the CPU installation process.

The only thing that is coming to mind here is that very concidentally the Power button on my case has gone out during the same time that I decided to do a CPU change out?

Any suggestions for me?

 

[franklin97355]

Check the power supply. You can test the start button by pulling the wires off the motherboard and momentarly shorting the two pins.

The answer is "42"

 

[JSD7878]

I hate to ask dumb questions but I must ask for a bit more info on how to do this, do you mean shorting the two pins on the MB directly? If so what do you recommend I use to do this with? Also are you saying that when I short the 2 pins that the PC will start to boot up bypassing the start buttton altogether if the PS is ok and if it doesn't then the problem is in the PS? Also the MB has an onboard LED and it is lit when I turn on the PS from the switch on the back.

 

[Ploper001]

Everything on the front of the PC case (power switch, HDD and power lights, front USB/Audio etc.) and the PC speaker are plugged in somewhere on the motherboard.

Find the ones that correspond to the power switch (your motherboard manual should tell you where they'd be plugged in), take them out, and then short them with a paper clip or something.

 

[paparazi]

Unplug everything that is not necessary (all addon cards, any periferals etc) leave just the bare essentials to minimise the possible causes, even the HDD's and roms, see if you can get it to at least POST.
Try using the cmos clear jumper to reset the bios (look in your manual)
If that doesn't work I would suspect that the power supply has failed "coincidentally" remember the FX55 takes a fair bit more power than your old 3200.

Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[JSD7878]

Hi Paparazi,

Ok will do, just to add the PSU I have in this PC is 2 months old and it's a 550W ANTEC, which should be up to the task right?

Should I not try and short the power switch pins before attempting to tear down my entire PC or are you saying tear down the PC first then attempt the short? Or are you saying skip the short?

Thanks for everyone's help thus far.

 

[paparazi]

Indeed! the Antec 550watt Truepower should be fine and is quality but I guess I've seen stranger things happen.

Try clearing the cmos first
Then pulling off the front panel wires and momentarily touching the pwr header pins
Then strip to bare minimum
Then if you still don't get a post! "bread board" remove the motherboard from the case and place on the motherboard box or similar with the absolute minimum installed ie:
1 stick of ram/CPU with heatsink and fan/graphics card/power supply, clear cmos, then momentarily touch those pwr pins.

Are you 100% sure all the additional power connectors that are needed on this board are being used?

Also, some boards often need a bios flash to recognise a faster/newer CPU, now I know you are saying your original CPU doesn't work either.

Something is preventing boot, lets find out what that something is!
Something may have become damaged and is now "crowbarring" touching ground! preventing Post.
Hmmmmm?? is the CPU fan a 3 or 4 pin type? have you fitted the fan plug correctly? as in, 3 pin on a 4 pin header? but in the wrong position.

Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[Johnthephoneguy]

The short is the easy test that only takes a minute, try that first, what youa re doing is testing the switch itself, if you momentarily short the pins on the MB then it will trick the MB into thinking you hit the power switch, thus telling the MB to turn on. If it doesn't work, then go ahead and try other troubleshooting.

JohnThePhoneGuy

"If I can't fix it, it's not broke!

 

[JSD7878]

Hi Martin,

Ok to my utter amazement and to my somewhat disappointment, I first cleared the CMOS, then removed the Video Card, the Sound card and stripped the computer bare. To my amazement the PC started right up. I immediately shut the PC down. Then I started adding one component at a time, and then restarted the computer, and each and everytime the machine would start. So now I have computer running, whereas yesterday it would not do so and so to my somewhat dissappointment Im not at all sure I know why...

But as suggested all of this did get me looking at PSU more closely, My Antec PSU is a 500W not a 550W, I also examined this today and notice the front fan is moving, the rear one is not, can this be normal?

Thanks All.

 

[JSD7878]

I called Antec they told me the rear fan only kicks on when the internal temp reaches a specific temperature, and that it's normal for this to occur.

My next question would be does anyone know what a normal range of temp should be for an AMD FX55 processor?

Another question I have to is I have a Leadtek WinFast PX8800 GTS on it's way, will my 500W Antec PSU be able to handle this as well?

My best as always.

 

[spudnuts]

The answer to your problem was simple, you didn't have something hooked up right. I've had many times where a simple wrong connection to the mobo will stop everything. It's just obvious by it working that you've solved that issue.

Just keep the temp below 65C, anywhere above 50C may impact stability but 65-70C and above is bad for an AMD chip.

Information Assurance,CCNP,CST

 

[JSD7878]

Thats just it I don't think I had any connection hooked up wrong, and I don't think I fixed anything. I would have preferred a Eureka moment, but fortunately and unfortunately I pushed the button and it worked.

 

[spudnuts]

I can't really tell you what it was and based on this discussion, you'll never find out because you'll never be able to replicate the problem.

Personally, i'd just let it go as one of them pure f'n magic things

It does happen to the best of us.

Information Assurance,CCNP,CST