Hi, I have a very annoying problem: my wired LAN connection is disconnecting/reconnecting automatically every few seconds. OS is Windows 7 x64, NIC is Marvell Yukon Gigabit Adapter 88E8056. Router is Negear DG834Gv4. What I have tried so far: manually set NIC speed mode (from auto negotiation to duplex, half duplex, 10 Mbps, 100 Mbps etc.), installed the newest driver checked with another computer (with another NIC) and confirmed it works OK with my router connected other computer with similar NIC (Marvell Yukon 88E8055) and confirmed this very same problems happening tried another network cable I have checked the Event Viewer and have many event sequences like this: 2010-10-21 22:58:04 Port A is down (source: yukonw7) 2010-10-21 22:58:06 The TCP/IP NetBIOS Helper service was successfully sent a stop control. The reason specified was: 0x40030011 [Operating System: Network Connectivity (Planned)] 2010-10-21 22:58:06 The TCP/IP NetBIOS Helper service entered the stopped state. 2010-10-21 22:58:06 Port A is up with 100 Mbps. 2010-10-21 22:58:06 Duplex State is Full Duplex 2010-10-21 22:58:06 Pause Function is Rx and TX 2010-10-21 22:58:07 The TCP/IP NetBIOS Helper service entered the running state. 2010-10-21 22:58:11 Port A is down [and the sequence repeats] [......] Sometimes there are those NetBIOS Helper events and sometimes not. I have internet access, of course except for the short moment the LAN connection is lost. I have spent much time reading about similar problems but haven't found a solution. I can provide Event Viewer logs if needed. Regards, Tom

Hi, thank you for posting here. After checking you issue, it seems the problem with Marvell Yukon NIC. As the issue did not appear on another pc with another NIC, but occurs other pc with Marvell Yukon 88E8055, I suggest you asking the manufacturer for further help, or ask for the driver which compatible with Windows 7. And does this issue appear before? If it doesn’t appear before, you can perform a system restore for test: System Restore ============= 1. Click the Start Button, type "system restore" (without quotations) in the start search box and press enter. 2. Click "Choose a different point" and click next. 3. Check Show more restore points box. 4. Choose a date before this issue happening, and click Next. 5. Click Finish. Hope it helps. Regards, Leo HuangPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, Thanks for your reply. The issue hasn't appeared before, it surely must have been introduced with Windows Update or NIC Driver update. It's driving me nuts - imagine having your internet disconnected every few seconds. I have the newest NIC driver, I don't think Marvell will help but maybe I'll try contacting them, this is 100% reproductible error so it could be useful to dig deeper into it. Both PCs affected are using Windows 7 64bit. I'll also try system restore later but as you know this isn't a perfect solution, this is happening for quite some time now, I can't remember exactly when it started. -- Tom

Hi, if the issue related with Windows Update, System Restore is a quick solution to solve this problem. Or you can go to “Programs and Features”---“View installed updates”, uninstall the updates for test. Regards, Leo HuangPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

I don't have a restore point for that time period. As for the Windows Update - it's impossible for me to identify the particular update that might have caused this problem - there are many of them. I wish there would be some real diagnostics built in Windows to solve this kind of issues. As for now I ordered Intel Gigabit CT adapter and I think either Microsoft or Marvell should refund it to me ;) I have read many negative feedback about Marvell integrated LAN adapters and when I'll be looking for a new motherboard or laptop this surely will be the thing to avoid.