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How to diagnose hardware problems

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August 27, 2009 3:37:45 AM

Is there a rule of thumb method for diagnosing which components may be fried if your PC does not start up? I have a newish PC I got from one of those eBay store resellers (cowboom) that will not boot up when turned on and would like some help in figuring out where the problem lies. Here is the problem I have been having:

PC was completely functional one day, then powered down normally in Windows. The next morning, I pressed the power button and no POST beeps, no BIOS page, no video, no hard drive access noises, nothing. There were no hardware or software changes during this time, and no power losses or surges that I noticed. Currently the only thing that happens when the power button is pressed is the CPU fan, case fan and power supply fan all turn on, and the DVD drive spins briefly. There is power getting to the DVD drive, since I can open and close the drive tray. Holding down the power button for several seconds shuts off the PC like it normally should, but the power supply fan is now always running as long as the power cord is connected to my power strip. I have unplugged the cables and power cords connecting the motherboard to the hard drive, DVD drive, video card, RAM modules and all PCI cards. THis has not been successful in booting up either. Any ideas?

Here my system specs:
Acer Aspire T180 desktop
2.3 GHz AMD Athlon 64 X2 4400+ dual core
1 GB RAM (2 x 512MB Nanya PC2-5300 DDR2)
Hitachi Deskstar SATA HDD 320 GB
250W Delta Electronics Power Supply
FoxConn MCP61PM-AM motherboard (i think)

Thanks!
a b à CPUs
August 27, 2009 4:01:46 AM

250W Delta Electronics Power Supply sounds like the culprit.
August 27, 2009 4:34:08 AM

it could be your power supply, thats a very low watts there, but you said the cpu motherboard and dvd turn on, then the power supply is giving power to turn on the computer, and it worked before on that power supply.

so everything turns on except you cant get a screen on your monitor correct?

if that is so, might be your graphics card try using the vga that is in the motherboard, also take out the battery from your motherboard out for about 10-15 mins to rest the defaults for the bios.

put the battery back in the motherboard use the motherboard built in vga, and turn on your computer.

hope that helps.
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a b à CPUs
August 27, 2009 4:48:00 AM

You may have a stick of memory that didn't travel well in shipping. Try 1 stick at a time and see if she boots.
a b à CPUs
August 27, 2009 5:08:16 AM

My vote goes to the psu.
a b à CPUs
August 27, 2009 5:12:23 AM

You've done a pretty nice job trying to isolate the problem, and that's the essence of troubleshooting these things.

First off, I'm guessing you can't or don't really want to return the PC. You didn't build it, so is there some form of warranty?

Second, the odds are quite good that the problem is a failed power supply. Once a PC is working, the first component to go is usually the psu. Especially when its an obviously inexpensive unit. So, you might try seeing if you can swap the psu . . . to save shipping on the whole PC.

If you can't do that - or borrow a psu from someone - you might buy this:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Its a psu that will work for you for quite a while, and worst case can be used as a backup for future troubleshooting.

Remember, it could be a different part that has failed, but the odds are its the psu.
August 27, 2009 12:11:06 PM

Thanks for all your suggestions. To answer some of your questions:

- I don't have a PCI video card, I am using the onboard VGA port.
- There is no warranty info I could find from the vendor on eBay I bought it from. I am afraid I am stuck with it.

A few last questions from me:
- If I replace the PSU, do I need to match the form factor for my case? I believe I have a micro-ATX case, will that 420W PSU you recommended work for my case?

- Even if I currently see power being supplied to the CPU fan, case fan and DVD drive, the PSU can still be broken?

- If I replace the PSU and still no change, does that mean I am looking at a new motherboard? or CPU?

Thanks again!
August 27, 2009 12:21:16 PM

someguy7 said:
250W Delta Electronics Power Supply sounds like the culprit.


I agree, that's my gut feeling as well.
August 27, 2009 12:23:17 PM

spencerfire said:
If I replace the PSU and still no change, does that mean I am looking at a new motherboard? or CPU?


I have only seen a processor go bad twice in my career, but I have replaced hundreds of motherboards. If you replace the PSU and it still doesn't work the motherboard would be my next guess.
a b à CPUs
August 28, 2009 2:40:52 AM

spencerfire said:
- There is no warranty info I could find from the vendor on eBay I bought it from. I am afraid I am stuck with it.
Not a good way to buy something . . . especially from a guy named cowboom, eh?
spencerfire said:
- If I replace the PSU, do I need to match the form factor for my case? I believe I have a micro-ATX case,
No, mATX and ATX share the same spec for the cross-section of the psu. The only issues with psu size are the length of some of the high-powered units vs some cases. When length is an issue, its not a function of the form factor - it can occur in either type case..
spencerfire said:
will that 420W PSU you recommended work for my case?
Yes.
spencerfire said:
- Even if I currently see power being supplied to the CPU fan, case fan and DVD drive, the PSU can still be broken?
Yes. Power supplies have many failure modes. Sometimes cable(s) goes completely dead. Sometimes the psu is no longer capable of delivering clean power and/or enough power. If the damn things would just go dead, we'd all have less gray hair :) 
spencerfire said:
If I replace the PSU and still no change, does that mean I am looking at a new motherboard? or CPU?
Let's cross that bridge in the unlikely event we come to it.
September 2, 2009 2:57:18 AM

So I replaced the PSU with a nice new one from PC Power & Cooling, and have 2 new sticks of RAM from Crucial. Unfortunately I am still getting nothing when I power up the system. So far here is what is happening:

I disconnected all components (RAM, optical drive, HDD, USB ports in front of case) from the motherboard and PSU, plugged a CRT monitor into the onboard VGA port, then flipped the PSU switch to ON and pressed the power button.

The PSU fan, CPU fan and case fan all turn on, but no video, no BIOS text, no POST beeps (I am not actually sure the mb has a PC speaker...). The power button light does not light up either, but that was the case before I replaced the PSU.

If I hold down the power button for 5 sec., all the fans turn off. If I press the power button again to start it up, nothing happens. Occasionally when holding down the power button for 5 seconds, instead of turning off, the CPU fan will start to spin really, really fast.

With the optical and hard drives are plugged in, I turn on the PSU and press the power button and I hear the HDD spin up and the optical drive light blinks briefly and I can open/close the drive tray.

I also tried removing and putting the RAM sticks back one at a time and in different slots, no change.
I tried removing the mb battery for about 15 minutes then putting it back in, then powering up, no change.

Any other ideas? If I have a faulty power button on the front of the case, would that cause any of this?
Thanks,
September 30, 2009 1:18:31 PM

:pfff:  I m having he exact same problem with my file server, no response from the screen despite all other functions working properly, PSU, USB, even tried changing RAM to other slots e.t.c and removing MB battery. Nothing.. Anyone have any other ideas.. Thanks for all the suggestions above though.
September 30, 2009 1:25:03 PM

Its either your PCI GCard is not set as default, your PSU doesnt have the balls :D  and/or your RAM has been damaged somehow.

Aso use default BIOS settings
:) 
September 30, 2009 1:27:02 PM

lonewolf_35 said:
:pfff:  I m having he exact same problem with my file server, no response from the screen despite all other functions working properly, PSU, USB, even tried changing RAM to other slots e.t.c and removing MB battery. Nothing.. Anyone have any other ideas.. Thanks for all the suggestions above though.



Have you tried another monitor (its obvious but its just a thought). :sarcastic: 

a b à CPUs
September 30, 2009 1:28:06 PM

Hmmm the next 2 best thing you could do now is either a video card or getting a new motherboard.
September 30, 2009 1:31:23 PM

seeing as how you have replaced your PSU and RAM im thinking its your MoBo, also swap the video leads just so you can safely say you eliminated the possibilty.
September 30, 2009 8:18:50 PM

Quote:
So I replaced the PSU with a nice new one from PC Power & Cooling, and have 2 new sticks of RAM from Crucial. Unfortunately I am still getting nothing when I power up the system. So far here is what is happening:


can you provide the specification about the new specs.
December 28, 2009 6:54:33 AM

I Have also T180 with the same PSU Delta Elec. 250Watt.
Ik added a new PCIe videocard in de pc and this worked well. Then i have replaced the PSU with a new Coolermaster 460wattPSU so that he could give enough power to the system. But then the system had the same problem, so the system turns on but doesnt boot, no display nothing Then I have put the original PSU back and this works fine. What can be the problem ?
a c 172 à CPUs
December 28, 2009 12:02:31 PM

SB, your new, excessively mediocre CoolerMaster is probably DOA.
December 28, 2009 9:33:18 PM

There is a possibility that the motherboard is shorting to the case. I had this issue with several computers that were shipped. The case flexed in shipping causing a short, making it not boot. Repositioning the motherboard in the case seemed to fix the issue for me.
!