ASUS P5B ethernet and shutdown/restart issues

Hey everyone. I just finished mounting an ASUS P5B motherboard into a case. I had some spare parts lying around and figured I'd put together a secondary rig. The PSU is fairly recent, only a few months old, 550W with active Power Factor Correction. It isn't anything fancy, but it gets the job done. This build is running an Intel Core 2 Duo E8400 with an aftermarket cooler (just swapped the thermal paste today), 2 GB of DDR2 1066mhz OCZ, and an NVIDIA GeForce 9800 GTX.

Here’s the issue. The PC boots up and Windows 7 64-bit runs fine, except for the internet. Device Manager shows the drivers for the adapter are fine—it's an Intel Ethernet—but the system tray in the bottom right corner says there are no connections available. I tried troubleshooting, and it claims the Ethernet cable isn't plugged in, even though I know the cable works perfectly on another machine.
On the Ethernet port itself, both LEDs stay lit constantly, whether the cable is plugged in or not. Even after a full reboot, they won't turn off.

Now, for a second problem. When I try to shut down the computer, it powers off, but then immediately turns itself back on. I have to hold the power button down to force it to stay off.

Any ideas? Thanks, everyone.

First off... this is a top-tier motherboard.

Check the BIOS battery. Is it sitting higher than 3.20 volts?
Perform a CMOS reset, go back into the BIOS, select "Load Optimized Defaults" or whatever similar option you see, then save and exit. Check again to make sure the "LAN" isn't disabled.

Based on what you've told me... if that doesn't work, you might need to manually configure a new network connection within Windows.

If it still fails, a lightning strike through the phone lines could have fried your router or the onboard Network Chipset. You can always just install an old or new PCI LAN card... then just disable the onboard LAN in the BIOS. It'll still be better and more stable than
buying some cheap USB Wi-Fi dongle.

If your graphics card is running fine, your PC is stable and you have a signal. That means your power supply is strong enough.

Good luck.

John Turner34 said:First off... that's a killer motherboard.

Check your BIOS battery. Make sure it’s reading higher than 3.20 volts.
Try a CMOS reset. Go back into the BIOS, select "Load Optimized Defaults" or whatever similar option is there, save, and exit. Then hop back into the BIOS one more time to make sure the "LAN" setting hasn't been disabled.

Based on what you've described... if that doesn't work, you might need to manually configure a new network in Windows.

If it still fails, a lightning strike could have hit the phone lines and fried both your router and the onboard Network Chipset. You can always just slap an old or new PCI LAN card in there instead. Just disable the onboard LAN in the BIOS first. It’ll still be much faster and more stable than
buying some cheap USB Wi-Fi dongle.

As long as your graphics card is running, your system is stable and you're getting a picture. That means your power supply is plenty strong enough.

Good luck.

Thanks for the reply! I'm going to try all of that, along with a clean installation of Windows. The drive in this CPU currently has an OS on it that was previously installed on a nearly identical board where all the drivers matched perfectly. Almost. =) I'll let you know how it goes. Thanks again.

Hey. I’ve tried everything. Reinstalled Windows, reset the CMOS, dialed in the optimized defaults in the BIOS, and even swapped out the power supply to rule that out. I updated the drivers for the Intel Ethernet too—Device Manager says everything is installed and working perfectly. Nothing helps. The only thing that actually changed is the reboot issue after shutdown; now it powers down normally and just won't kick back on. Right now, the LAN port is the only broken component. Interestingly, the LEDs on the LAN port stay lit constantly. As soon as I flip the switch on the PSU, they light up, even though the PC is still technically off. It feels like there's a short circuit somewhere. I even tried disconnecting the last four pins on the 24-pin connector and the ATX connector, but no luck. The fix is obvious: just grab a new PCI LAN card. But it bugs me that the onboard port died for no apparent reason. This board was running fine until a week ago, and the fact that it just stopped booting after being shut down... something isn't right.

Just because your onboard network card was working fine until a few days ago doesn't change the fact that it's clearly dead now. It happens. Honestly, your best bet is to just pick up a dedicated PCI LAN card and then go into the BIOS to disable the one built into the motherboard.

Yeah, it’s likely a faulty Network Chipset because if you unplug the cable from it, nothing should be lighting up at all.

shadowlynx102 said:Just because your onboard network card was working fine until a few days ago doesn't change anything. It’s clearly dead. Just grab a PCI LAN card and disable the onboard one in the BIOS.

Got it. I'll pick up a PCI card. Honestly, though, I've dealt with dead onboard LAN before and never seen a port light up like it's short-circuiting. That's why I was worried about the power supply or something else frying the board, but everything seems fine.