Need Help! No POST on boot.

[adamspbear]

My computer has worked well for quite some time and has been well maintained. Suddenly the image on the monitor was gone during a WoW (World of Warcratf) session. I checked all cables and the monitor and they were fine.

So I turn off the computer and turn it back on and notice it didn't POST (meaning no beep) or show an image on the screen. All fans and lights were running.

I have tried replacing the CMOS battery, checked ram chips, and checked for loose cables. Also the video card works in another system (which is the nvidia GeForce 6600gt). All I have narrowed it down to is the psu and motherboard as potential problems but it could be something I haven't checked.

What could be the problem?

All help is appreciated. Thanks.

 

[lordslashstab]

ok ok, i know your problem. What you need to do is unplug your comp from wall, take off your heatsink, and take out your processor and stare directly at it for 10 seconds. Then put it back together. should start up after that. If you have good ears and can hear voltage, you'll notice the capacitors clearing once you take out your processor.

 

[chaynz]

Typically, the systematic approach to diagnosing a system is as follows:

Cables, connections, etc... You already did this.

I'd normally say test the PSU's voltage lines (+12, +5, +3.3, GND, +3.3vsb....), but I'd think if you had the means to do this, you already would have. At any rate, swap in a known good PSU, or verify that yours is good (don't use it in another computer, the potential to fry your buddy's computer is very real if your PSU is bad).

Unplug EVERYTHING except for the PSU and the CPU/heatsink. Yes, even the ram. power it up. If it beeps, the system is at least searching for the memory, narrowing the possability of a mobo failure. If you hear it beeping (I forgot that beep code), reinstall the RAM. The beep code should change to a "no video" code (long, short, short, short). If it does nothing with your ram, swap the ram with a known good stick. If that doesn't yield a "no video" beep code, I'd be willing to point my finger at the motherboard.


You'll need some good silver heatsink compound and possably a (plastic) scraper of some sort depending on weather or not you'll need to remove some cheap OEM Headpad transfers. DO NOT REUSE A HEATPAD!!! They're a one-time-only thing. That includes the aluminum ones, the soft "rubber" ones, and old heatsink compound.

Before condemning the motherboard, swap your CPU into a different computer. Don't put a good one into yours; your motherboard may fry it if the voltage regulator or related circuits are damaged. Obviously, if your buddy's computer won't post with your CPU in it (and making sure it's not overclocked; set everything to auto detect [if applicable] before the swap), you need to replace your CPU. But CPU's USUALLY don't just go bad (unless you're running a non-thermal protected CPU, aka: a Dinosaur) for no reason. As a general rule of thumb: if the CPU pops for no appearant reason (overclocking, loose heatsink), replace the mainboard, too. Also, sniffing around the large capacitors for a fish smell (if they're electrolytic) is a dead giveaway to a bad voltage regulator. Also, if you see pieces of brown paper (mica capacitors), buldging capacitor shells, or lifted cap shells, those give it away, too.

Things to note:

Some integrated systems (Dell, Compaq, some HP's) will NOT POST if they don't detect that a monitor is connected. You shouldn't have this problem.

The majority of fluke no-POSTs are caused by IRQ conflicts with the video card or other devices.

If a BIOS gets fried, they'll usually boot with a "Boot Block" BIOS. It just initializes the most basic inputs/outputs so you can reflash your BIOS with a boot diskette.


hope it helps!

CHayNZ

 

[adamspbear]

Well, I unpluged everything but the cpu, heatsink, and motherboard and there weren't any beeps once again. I wish I had a multi-meter at home so that I could test voltages on the PSU. I will have access to one tommorow in class and I will see how that goes.

Does anyone have any answers regarding the no posting with everything unplugged except fot cpu/heatsink and mobo?

Thanks for the reply chaynz, it was greatly appreciated and hopefull we'll get this issue solved.

 

[lordslashstab]

[/quote]well you didn't unplug the cpu so there is your problem. blah open your eyes