Flashing Desktop, on and off

[Andrew Evans]

Hi Everyone.

The last week or so, a desktop on one computer(1st) (on a network with multiple computers) begins to flash off and on. The desktop is not responsive at all, however I can open programs like outlook or chrome and use them while behind, the desktop is flashing.

I have found out that if I restart a different computer(2nd) on the network the flashing stops! While the first computer I mentioned is flashing, a third computer(3rd) on the network will have the spinning circle on the mouse pointer, spinning of and on constantly. And again once I restart that network computer(2nd) the flashing on the 1st computer stops and the spinning circle on the 3rd computer stops...That 2nd computer threw a "sihost" error, but I only seen that once.

I have turned off the recommended services listed on other forums, I don't see any of the 3 programs Microsoft has said caused this installed.. And I have done complete virus removals on the computers.. During the scans it found minimal items and nothing too serious.

I am not sure what to do... Every time I think it is fixed the issue comes back. I have been a tech for 10 years or so and never came across anything like this?

If anyone has any insight or solutions please let me know. My clients needs to be up and going correctly.

 

[Old Guy Geek]

Well, the fact that working with another computer on the network causes it to stop or start makes me think that the computer is trying to present you with a dialogue box about duplicate IP addresses. I haven't seen it for years, but when 2 computers are set to use the same IP I think a dialogue warning box pops up letting you know about the conflict. Maybe in this case, Windows 10 isn't giving you the box but the desktop is trying to display it, but it doesn't for some reason.

Are you using static or automatically assigned IPs?

 

[Andrew Evans]

I will have both computers here in my office shortly.. So I will check.. I am thinking dynamic simply because I only set up a static if I need one, ex. remote access or someting.. but I will check it out.

If I did not hear from anyone, I was going to reformat and start over.. its been a long week or so trying to make this not happen anymore.. it started after they updated to windows 10 about a week and a half ago.. I am just wondering if the systems files were damaged during the update. Not sure how they did this after 7/29/16 as the free upgrade ended.. maybe it was already downloaded or something... I only know of using assistive technology to upgrade after 7/29/16..But my client would no know that.

 

[Andrew Evans]

I think I might have it narrowed down...(Hopefully)

What I have done since I posted my question...

I ended up reformatting the HD and installed a clean windows 10.
Reinstalled the bare minimum software my client needs to operate.
And on Sunday(yesterday) I set up the computer back in their office.

As I was finishing up the set up(getting printers connected and what not) the computer started flashing again!

I thought maybe the issue was because of IP address conflicts, but after checking the router every device add a unique ip via DHCP. There was one device(commercial printer) that had a static ip.. Printer company must have set that up..

There are about 5 computers on the network and this is the only one doing this flashing thing.

Do you think the lan port could be bad?

I am going to connect to the network via wifi and see if that changes anything...

I noticed yesterday, that when I plugged in ethernet cable it took a while to obtain ip address and get internet access...

I have swapped computers at another station in the office and this same computer is flashing at another station! I have a feeling it might be a damaged lan port.. The ethernet cable was pretty tight at the first station, so it could have damaged the port if the computer was pulled out at all...

Let me know what you guys think, thanks again for your help.

 

[Trouble]

The computer exhibited symptoms when in "the" office, but not when relocated, then the symptoms returned when it was returned to "the" office.
You suspect a damaged Ethernet port on the NIC.
I would think that using device manager to disable the Ethernet adapter and unplugging it physically from the Cat5 connection would provide some diagnostic value.

Unless the NIC was damaged internally resulting in some electrical noise (broadcasting) or a short, in which case I would expect to see other symptoms other than a flashing screen / desktop.
Perhaps if possible, even disabling it in the BIOS if that is an option, might further the diagnosis.

 

[Andrew Evans]

Ok, we currently have the computer connected via wifi.

I did forget to mention that when it started flashing yesterday, as soon as i disconnected the ethernet cable the flashing stopped..

So know we will wait to see if it happens again.. i will also disable the device in the device manager.

Thanks for your support.

 

[Andrew Evans]

So the computer started flashing again.. on wifi.

I guess that ruled out the lan port...

So more details about the network:

We have one computer that acts as a server where all the company files are stored. There are 3 folders under "Documents" that I have shared. On that server computer I have 3 user accounts, one is what the client uses and the other 2 I named network user & network user 2.

So the 3 users on this "server" computer are:

Office (client uses this user to work on computer)
Network User
Network User 2

Out of the 3 folders that are shared, one is shared to "network user"; another one is shared to "network user" & "network user 2" and the 3rd folder is a folder for the owners which is only shared with the Main user account.

Now, on the computer where the desktop is flashing/blinking, I used the "network user" credentials so this employee only has access to one folder. So I have a mapped network drive pointing to that folder.

The other computers on the network are set up the same way, and vary which user credentials they have, depending what they need access to.

No other computer on the network is having issues.

Is there something wrong with the "server" computer that holds all the files? When I restart the "server" computer, the flashing stops on the problem computer.. Very frustrating!

 

[Trouble]

The computer name, the IP address and believe it or not the MAC address of the Network adapter must be unique. So double check all three and confirm that they are in fact not duplicated elsewhere on the network. Although extremely rare I've seen a MAC address cause network issues.
ipconfig /all -> Physical Address -> Hex Number
Example: Physical Address. . . . . . . . . : FC-AA-14-9C-2F-D6
Compare to other machines (network nodes, including printers).

Try disabling IPv6 on everything and see if that changes anything.
Take your time and see if you can determine which machine on the network doesn't like playing with the machine that is symptomatic
IF you can find the machine that is causing the problem machine to freak out, turn it off and see if everything is OK with all other nodes turned on including the problem machine.

I suppose that it's possible that at some point in time something got cloned and now they don't want to play together on the same subnet.

 

[Saltgrass]

I have seen some comments from Microsoft concerning downline syncing.. If the situation effects networked systems I suppose you might look at that.