weird boot problem... please advise 2

[fl35h]

hi, my computer just started having this problem where it wont boot. if i hold down the power switch then then the power comes on and my case fans and lights turn on, but the PC doesnt boot. and if i let go of the button then it turns off. its weird because it was working real well about an hour before this started happening. i was gamming at my brothers house and it was working fine there. but, when i brought it home it started having this problem. another thing is that it is quite humid here so that might have caused some problems. im not sure what part is bad or needs replacement so any help would be appreciated.

here is my system:
Antec 900 case
Asus P5N-E mobo
C2D E6750 2.66gh @ 3.2 gh
8800 GTS 640
550w PSU
2 gigs OCZ DDR2 ram

 

[fl35h]

sorry for the double post, but i couldnt find a edit button on this page.
but i went back today and checked my PC and it wont turn on at all. not even if i hold down the power button. but the green light on my mobo is on.... so is it the PSU?

 

[LesNicholls]

It sure sounds like a PSU problem to me.

 

[BadBigBen]

first thing first,

i was gamming at my brothers house and it was working fine there. but, when i brought it home it started having this problem.

could be that something was knocked loose...

check:

1.) Heat Sink Fan for proper seating and if it is plugged into the correct header... most mobo's will not POST when they detect that a HSF is not installed or disconnected (CPU getting HOT), preventing a burn out of the CPU...

2.) Check the seating of the GFX-Card, misaligned PCI/AGP/PCIe/PCI-x cards can cause the same symptoms...

3.) check proper seating of RAM modules...

4.) check proper connection of powered peripherals (CD/DVD ROM, HDD)...

if the above do not cure it, then check the PSU, by using a test PSU (borrow from a friend or brother, etc.)

Post back and good luck...

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[fl35h]

thanks guys for the replies.
i didnt check all the parts to make sure that they were in properly but i will do that now.

 

[fl35h]

nope thats not the problem still nothing.... . i guess i'll have to try a new PSU then....

 

[G0AOZ]

I'd certainly try changing the PSU as suggested by BadBigBen.

If you can hold the power button in and get into the BIOS, check that the indicated temperature of the CPU isn't too high.

From your post it seems you're overclocking. Again, if you can get into the BIOS, just try temporarily knocking back the speed to normal.

ROGER - G0AOZ.

 

[BadBigBen]

something popped into mind, some PSU's have a safety which kicks in when they loose power or get a surge (this can be from unplugging and plugging up the power line)...

to reset it to normal, unplug the power in the back of the PC, then hold the POWER ON button for a minute or more...

also check the POWER switch, if it is seated correctly, or if it is damaged. How to check for damage, simple either switch the connector with the RESET Button connector (turning on the PC over the RESET switch then) or bridge the connector with a screwdriver...

also G0AOZ, brought me to another idea, about overclocking, reset the CMOS, by either the jumper (read the manual as to where it is) or by taking out the battery for some time... You will have to reset the time and date later, but worth a check...



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[fl35h]

ok thanks eveyone for the replies and tips. i wont be able to get another psu till next week so i guess i'll try the other steps G0AOZ and BadBigBen mentioned. and the when i get another psu i'll try that.

 

[fl35h]

ok here is an update:
i tried BadBigBen's tip and held the power button down for a minute or more with the PSU power cable unpluged. after a minute i plugged it back in and when i hit the power switch my case lights and fans went on for about 2 to 3 seconds before turning off. now its back to the same state as before with no response at all.

 

[BadBigBen]

Like I said, that could have been it, but unfortunately it wasn't...

it does sound like a safety mechanism is cutting in, preventing damage to the CPU...

alternative to testing a new PSU, you could test your PSU in another PC or have it tested at a local shop...

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[fl35h]

ok well i already bought a new psu and will test it tonight. luckiliy my brother is building a new pc so im testing out his PSU.

 

[fl35h]

ok well bad news, i got a new psu and plugged it in and still nothing. the led on my mobo is on but nothing happens when i press the power button. now im begining to think its my power switch connector. i tried to jump stasrt it with a screw driver but that did nothing. any ideas?

 

[wahnula]

i tried to jump start it with a screw driver but that did nothing. any ideas?

Are you positive that you shorted the two correct pins? The ones labeled PWR SW? If so and nothing happened then that could mean a mainboard fault. This means you cannot now enter BIOS, correct?

Tony

Users helping Users...

 

[BadBigBen]

now it's time to BREADBOARD it...

by taking it out of the case, setting on a nonconductive surface (motherboard cardboard box for example) BUT ground yourself first in order to discharge electric static (it's a killer for components)...

hook up only one stick of RAM, the PSU and the GFX CARD (monitor of course), nothing else!

if it posts now, then one of the other peripherals is the culprit...

if it does not post, then try another stick of RAM,
if that does not work, try another GFX card (e.g. the one from your brother), if that does not work,

then it boils down to either the motherboard or CPU as being the problem here...



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[fl35h]

ok well i finally got a chance to do some work on my PC now. i got a new motherbord. ASUS P5Q - pro. installed it and when i hit the start button the lights and case fans go on. this is somewhat of an improvement from before because when i would hit the power button nothing would happen, and now the lights and fans work. but now there is another problem. i dont get any signal on my moniter. i tested it on another computer and the moniter is not bad. i also tested it with different cables. also i tried another graphics card (9800 GTX) and still the same thing.i took out all HDDS DVD drives and tried again but still nothing. no image. any ideas on what it could be?

 

[BadBigBen]

On new mainboards I usually clear the CMOS first, this is to ensure that previous settings are cleared...

question: any beeps?

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[fl35h]

no beeps.... and whats CMOS? and how do you clear it?

 

[BadBigBen]

CMOS is in this relation, BIOS, the area where the settings are stored at...

there is a jumper on, almost, every motherboard usually a 3 pin connector near the battery, with markings called CLR_CMOS or CLR_CMS, you can get the same effect by taking out the battery for a few minutes (unplug the PC from the outlet, just to be sure that the PSU does not supply the power to the CMOS) and then holding the power button down, in order to drain any capacitors that may supply power for a while...

other things to check, the no post situation:

seating of gfx-card, ram, and HS-Fan...

unplug the HDD, CD/DVD and any front USB cables from the mainboard...


Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[fl35h]

ok well thanks guys for the help here. i really appreciate it. my PC is working now well, not entirely. turns out the motherbord was bad so i replaced it and then found out that my graphics card is also bad. so i'll need to replace them. im debating between the 9800 GX2 or the 260 GTX which is cheaper.... any ides?