Motherboard or Windows?

When I turn on the computer, the POST beep is normal. After the POST beep, there are long, lower pitched beeps that continue erratically (each varying in duration) as if the computer is overheating until the log on screen, while Windows is loading. On two occasions it has continued beeping even after logging on. The beeping varies with the USBs that are plugged in before turning on the computer. On several occasions, the computer freezes at "Windows is loading" and I have to turn it off by holding the power button and turning it on again.

When restarting the computer, there is no POST beep. There is only one short, low pitched beep (I'm positive it's not the POST beep).

However, if I switch off the computer for a few minutes (including and excluding the wall switch) and turn on the computer, everything will be normal. POST beep is fine, and no other beeps after that. Windows loads fine. If I turn off the computer to let it cool down for a few hours and turn it on again, it will resume the beeping mentioned in my first paragraph.

I suspect that a solder might not have been done properly on the motherboard, as when the computer is warm it seems to start normally (softening the solder and improving the contact).

Despite the abnormal starting, I am not experiencing any troubles with my computer once (IF) it has loaded.

System Specs:

OS: Windows 7 Ultimate x64
Motherboard: GA EP-45-DS4P (TPM chip is not activated. Both NICs also disabled, I'm using a USB Wireless adapter.)
CPU: Q9550
RAM: 2 x 2GB SuperTalent DDR2, 2 x 2X 2GB Corsair DDR2 (I've ran MEMTEST multiple times, passing many cycles. I'd assume the RAMs are fine.)
GPU: ATI 4850
HDD: 1 x 1TB Western Digital (SATA) (boot disk), 1 x 500GB Seagate HDD (SATA)
PSU: Corsair 650W

Additional Hardware:
1 x ASUS DVDRW
1 x Lite-On DVDRW
1 x Card Reader
1 x Floppy Drive

USBs that I plug in/out:
LG KF750
Microsoft Wireless Mouse
Dynabook USB Mouse (not anymore, but it also gave the same problem)
iPod Touch
D-Link Wireless Adapter (always plugged in)

It's been happening for a few months, the parts were purchased and assembled in October 08. Shop warranty is 1 year, but I've heard that the manufacturer's warranty is 3 years, I'm wanting to avoid bringing it in for repair.


I'd appreciate it if anyone could give input, I'm unsure if the motherboard is still covered by warranty as I've had it for over 1 and a half years. I'm considering plugging out the existing hard drives and plugging in one temporarily and loading Windows on there, to rule out whether it is the motherboard or not.

EDIT:
I've booted the computer on Linux (Knoppix 6.2.1) from a CD, and it has still beeped the same way. The only thing now is to rule out which one of the hardware is causing the problem. IMO it does not sound like it is related to the PSU in any way, but I'll try replacing it with another one. Is there any way I can rule out the graphic card? I do not have a spare PCIE graphic card that I can test with.

I'd say motherboard, AFAIK windows will not cause POST beeps.

If you have a spare hard drive somewhere you can try to see if it's windows causing the problem by installing an OS on that HDD. But I'd say it's highly unlikely.

PS your sig kinda scares me

I'm sure the beeping is not the POST beep, as Windows wouldn't start at all if it were.

http://www.computerhope.com/beep.htm

This should cover the part of 'which beep code means what'.
I can't really find out which code you have exactly in the way you described it.

Are you sure that the PSU is doing good?
To me your problem sounds like capacitor damage on the first hunch.

However,

Is your setup a custom build, or built on top of a complete system?
Whats your PSU?
Do you have any spares for testing?

@SnOwBunZz:
I have yet in my life to see a BIOS that correctly adheres to POST sound-code "standards".

Quote:

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Originally Posted by Ronin

@SnOwBunZz:
I have yet in my life to see a BIOS that correctly adheres to POST sound-code "standards".

---

It's still a step closer to knowing what the beeps mean. I could search for the exact meaning of the beep as long she would post clearly how it beeps (or meaning me less drunk, since I'm on a Polish b-day party, which you should read as quite a bit of alcohol) and who made the BIOS (ami-bios, phoenix etc).

Yes, it is a custom built. PSU is Corsair 650W. I'll test with a spare and see how it goes.

@snowbunzz
Like I said, I'm pretty sure it's not the POST beep that is the "beeping" that I am referring to that is happening. The beeping happens after the POST, while Windows is loading. The beep is much like the beep that indicates the computer is overheating, but the computer starts fine and runs without any trouble.


Updated original post with more information.

Well I understand the following:
When you boot a PC, the motherboard does a "power on self-test".
Every signal during that time is a POST notification.

You say that the beep occurs after this test is already finished?

@USB:
I had various issues with USB peripherals connected on boot.

I am not completely clear on what kind of testing you did;
As I read it you did the following two which did not change the problem "significantly":
- Boot minimal config (no mouse, no additional HD, no disk drive, no floppy, one RAM, no case fans, no peripherals, no networking)
- Boot normal config with no USBs at startup (some USB devices are just problematic; That for me includes my ipod btw)

You could to make it definite that it's not a POST, take out one piece of hardware from the minimal config and check if the bootup process works out like before (try booting no RAM, not video card, no monitor, etc.), thought you should be able to see the ram check if you did disable the BIOS logo.

btw, using 2 brands of RAM together is already risky business in the compatibility department.
Did you try shuffling them around, or is there a recommended setup in the documentation?

However, there are steps I would recommend (do any you didn't already do);
Check all connections especially the power lines of the PSU (unplug, plug in again)
Set your fan speeds to continuous in BIOS (and/or load a fail safe mode)
Check that the BIOS battery is not depleted and/or badly connected

I've done a BIOS flash some time ago when the problem started occuring.