Pat, If you're running any firewalling software, software NAT, wireless link or VPN then you may see these problems. Broken router boxes can also cause problems of this sort, in my experience.
You may wish to check the Application Event Log of the server computer to verify that WinVNC4 sees the connection time out or get reset by some part of the network between viewer and server. Regards, Wez @ RealVNC Ltd. > -----Original Message----- > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > Sent: 06 September 2005 15:05 > To: James Weatherall; [email protected] > Subject: RE: Blank Screen Problem > > James: Yes that makes sense. Normally about 1 minute after the black > screen the window goes away if there is keyboard or mouse > movement. Any > ideas on why the connection would drop so consistently? > > Thanks - Pat > > -----Original Message----- > From: James Weatherall [mailto:[EMAIL PROTECTED] > Sent: Saturday, September 03, 2005 7:13 AM > To: Boland Pat-A19945; [email protected] > Subject: RE: Blank Screen Problem > > Pat, > > If the cursor doesn't move at the server and you don't get any updates > then this suggests that your network connection has been dropped. VNC > will take a short while to detect this because it relies upon > the TCP/IP > stack to do so. > > Regards, > > Wez @ RealVNC Ltd. > > > -----Original Message----- > > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > > Sent: 02 September 2005 15:21 > > To: James Weatherall; [email protected] > > Subject: RE: Blank Screen Problem > > > > James: > > I'm giving you a perfect illustration of my one-dimensional > thinking, > > sorry. No the cursor does not move and is not visible at > the server > > when you move it at the viewer. > > > > Kind regards - Pat > > > > -----Original Message----- > > From: James Weatherall [mailto:[EMAIL PROTECTED] > > Sent: Friday, September 02, 2005 7:02 AM > > To: Boland Pat-A19945; [email protected] > > Subject: RE: Blank Screen Problem > > > > Pat, > > > > I meant does the cursor move at the server when you move it at the > > viewer when the screen being shown is all-black. > > > > Regards, > > > > Wez @ RealVNC Ltd. > > > > > > > -----Original Message----- > > > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > > > Sent: 01 September 2005 23:06 > > > To: James Weatherall; [email protected] > > > Subject: RE: Blank Screen Problem > > > > > > James: > > > > > > Very good question. Yes the mouse works, but instead of the > > usual > > > white arrow, I get a small (very small) white box as the cursor. > > > I cannot tell if the keyboard is working as all I see is > the black > > > screen. > > > > > > I will look for logged errors in the application event log. > > > > > > Any viewer that connects sees the black screen unless the Server > > is > > > reset, according to how I explained before. > > > > > > Server is running XP most viewers are running XP too, > > occasionally > > > Win 2000 is used on the viewer side. No difference in the black > > > screen problem. By the way I did turn off fast user > switching, no > > > effect. > > > > > > Kind regards - Pat > > > > > > -----Original Message----- > > > From: James Weatherall [mailto:[EMAIL PROTECTED] > > > Sent: Thursday, September 01, 2005 6:39 AM > > > To: Boland Pat-A19945; [email protected] > > > Subject: RE: Blank Screen Problem > > > > > > Pat, > > > > > > When you re-connect to your server and find that the > > display appears > > > to be black, do the mouse and keyboard still work in spite > > of that? > > > Do you get any errors logged from WinVNC4 in the > > Application Event Log > > > > > on the server? > > > > > > Have you seen this problem with any other systems? > > > > > > Which operating system is the server running? > > > > > > Regards, > > > > > > Wez @ RealVNC Ltd. > > > > > > > > > > -----Original Message----- > > > > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > > > > Sent: 26 August 2005 22:17 > > > > To: James Weatherall; [email protected] > > > > Subject: RE: Blank Screen Problem > > > > > > > > James: > > > > > > > > Well, the VNC Server is running as a system > service on the > > > computer I > > > > am trying to access remotely so in the service mode. > > (But I don't > > > > think it make much difference I turn it on and leave it > running). > > > > Now on the viewer side initially everything is fine, I > > can see the > > > > remote server screen, and this will work indefinitely. > > But when I > > > > shut the viewer session down, lets say after 10 min. when I > > > bring the > > > > viewer session up again it connects but all I get is a > > > black or blank > > > > screen, the connection is present but the view of the > > > remote server is > > > > > > > not present. > > > > > > > > To get a non-blank screen session on the > viewer, I must have > > > someone > > > > at the remote PC shut down the VNC Server (service) and > > > restart it. > > > > Then on the viewer side I get both the connection and > the remote > > > > machine display visible on the viewer. > > > > > > > > I hope this helps clarify the problem. If not > maybe you have a > > > > specific question. > > > > > > > > Regards - Pat > > > > > > > > > > > > I'm afraid I can't really understand the description of > > the problem > > > > > > that you provide here. You refer to resetting the > > > > system, but then > > > > > > describe shutting down a User-Mode VNC Server and > > > > restarting it, as > > > > > > far as I can tell. Which do you actually mean? Are > > you really > > > > > > running VNC Server in User-Mode, or in Service-Mode? I > > > > also don't > > > > > > understand "After that time period however, all you get > > > > is a blank > > > > > > screen, if you shut down the local PC and try to > > > > establish another > > > > > > session, until you reset the remote server end again. " > > > > at all - if > > > > > > you've shut down the PC then it is off and will not > > respond to > > > > > > connection attempts at all. > > > > > > > > > > > > > > -----Original Message----- > > > > From: James Weatherall [mailto:[EMAIL PROTECTED] > > > > Sent: Friday, August 26, 2005 10:49 AM > > > > To: Boland Pat-A19945; [email protected] > > > > Subject: RE: Blank Screen Problem > > > > > > > > Pat, > > > > > > > > Sorry, I was hoping you would re-state the problem using > > > the standard > > > > terminology, since I'm afraid I was still a little confused > > > as to what > > > > > > > you were describing! > > > > > > > > The port used for RFB traffic is normally port 5900 > under Windows. > > > > > > > > Packet size is a fundamental characteristic of the > > > underlying network > > > > and has nothing to do with VNC (unless it's incorrectly > > > configured at > > > > one or other end, in which case it can cause network > > > applications such > > > > > > > as VNC to stop working). > > > > > > > > Regards, > > > > > > > > Wez @ RealVNC Ltd. > > > > > > > > > > > > > -----Original Message----- > > > > > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > > > > > Sent: 26 August 2005 16:30 > > > > > To: James Weatherall; [email protected] > > > > > Subject: RE: Blank Screen Problem > > > > > > > > > > James: > > > > > Thank you. > > > > > > > > > > To my other question: can you tell me What firewall > > > > configuration > > > > > ports need to be open, and what packet size should be > > used? What > > > > > settings on the client side interact with firewall if any. > > > > Is there a > > > > > timer on ports for firewall? > > > > > > > > > > Regard - Pat > > > > > > > > > > -----Original Message----- > > > > > From: James Weatherall [mailto:[EMAIL PROTECTED] > > > > > Sent: Friday, August 26, 2005 10:24 AM > > > > > To: Boland Pat-A19945; [email protected] > > > > > Subject: RE: Blank Screen Problem > > > > > > > > > > Pat, > > > > > > > > > > The relevant terminology is: > > > > > > > > > > User-Mode means VNC Server running as a normal > > application on the > > > > > computer you are trying to access remotely. > > > > > Service-Mode means VNC-Server running as a system > > service on the > > > > > computer you are trying to access remotely. > > > > > > > > > > The VNC viewer is simply called VNC Viewer, and runs on > > > the viewing > > > > > computer. > > > > > > > > > > Regards, > > > > > > > > > > Wez @ RealVNC Ltd. > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > > > > > > Sent: 26 August 2005 16:09 > > > > > > To: James Weatherall; [email protected] > > > > > > Subject: RE: Blank Screen Problem > > > > > > > > > > > > James: > > > > > > > > > > > > Thanks so much for the reply. Sorry, resetting the system > > > > did mean > > > > > > shutting down the VNC server side from a user account and > > > > > restarting > > > > > > it. Not to confuse the situation I am actually running both > > > > > the server > > > > > > > > > > > and client (from time to time) but it is the user-mode > > > > > (client?) I am > > > > > > > > > > > having the problem with. > > > > > > > > > > > > At the remote PC (VNC server side) VNC is shut down, then > > > > restarted. > > > > > > Either manually by someone in that location or via the > > > > service-mode > > > > > > (which always works). Once it is back up again there is > > > no blank > > > > > > screen problem (user mode) on the local side until the user > > > > > closes the > > > > > > > > > > > session via the firewall . Then if they try to > > > > reestablish a proper > > > > > > connection occurs but a blank screen ensues via > the firewall. > > > > > > Connecting directly > > > > > > without the firewall the connection establishes perfectly > > > > > every time. > > > > > > > > > > > > Let me go off in a different direction: What firewall > > > > configuration > > > > > > ports need to be open, and what packet size should be > > > used? What > > > > > > settings on the client side interact with firewall if any. > > > > > Is there a > > > > > > timer on ports for firewall? > > > > > > > > > > > > Regards - Pat > > > > > > > > > > > > -----Original Message----- > > > > > > From: James Weatherall [mailto:[EMAIL PROTECTED] > > > > > > Sent: Friday, August 26, 2005 5:53 AM > > > > > > To: Boland Pat-A19945; [email protected] > > > > > > Subject: RE: Blank Screen Problem > > > > > > > > > > > > Pat, > > > > > > > > > > > > I'm afraid I can't really understand the description of > > > > the problem > > > > > > that you provide here. You refer to resetting the > > > > system, but then > > > > > > describe shutting down a User-Mode VNC Server and > > > > restarting it, as > > > > > > far as I can tell. Which do you actually mean? Are > > you really > > > > > > running VNC Server in User-Mode, or in Service-Mode? I > > > > also don't > > > > > > understand "After that time period however, all you get > > > > is a blank > > > > > > screen, if you shut down the local PC and try to > > > > establish another > > > > > > session, until you reset the remote server end again. " > > > > at all - if > > > > > > you've shut down the PC then it is off and will not > > respond to > > > > > > connection attempts at all. > > > > > > > > > > > > Can you explain further? > > > > > > > > > > > > Regards, > > > > > > > > > > > > Wez @ RealVNC Ltd. > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > > > > > > > Sent: 18 August 2005 18:31 > > > > > > > To: Boland Pat-A19945; James Weatherall; > > [email protected] > > > > > > > Subject: RE: Blank Screen Problem > > > > > > > > > > > > > > James: > > > > > > > I tried loading different releases of VNC on > > > > both the remote > > > > > > server > > > > > > > side and the local PC, I have shut off fast user > > > > > switching nothing > > > > > > > helps this blank screen problem. When the system is > > > > reset at the > > > > > > > remote server side (shut down VNC server application > > > > and bring up > > > > > > > again) the full screen appears and remains up for as long > > > > > > as the local > > > > > > > > > > > > > server has an established session. If the local > session is > > > > > > shutdown > > > > > > > within 5 maybe 10 minutes of the reset, you will not see > > > > > that blank > > > > > > > screen. After that time period however, all you get > > > is a blank > > > > > > > screen, if you shut down the local PC and try to > > > > > establish another > > > > > > > session, until you reset the remote server end again. > > > > > > > > > > > > > > Help; Thanks - Pat > > > > > > > > > > > > > > -----Original Message----- > > > > > > > From: Boland Pat-A19945 > > > > > > > Sent: Tuesday, August 09, 2005 1:09 PM > > > > > > > To: 'James Weatherall'; [email protected] > > > > > > > Subject: RE: True color and extremely slow speed > > > > > > > > > > > > > > James: > > > > > > > I get the frame (boarder) where the remote > > > > server is suppose to > > > > > > > appear, but instead of the remote PC blue screen and > > > > > icons - or any > > > > > > > application that would be running, I get "black" which I > > > > > call blank > > > > > > > inside the viewer window. I hope that answers > your question. > > > > > > > Regards - Pat > > > > > > > > > > > > > > -----Original Message----- > > > > > > > From: James Weatherall [mailto:[EMAIL PROTECTED] > > > > > > > Sent: Tuesday, August 09, 2005 12:12 PM > > > > > > > To: Boland Pat-A19945; [email protected] > > > > > > > Subject: RE: True color and extremely slow speed > > > > > > > > > > > > > > Pat, > > > > > > > > > > > > > > Can you explain what you mean by "blank screen"? > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > Wez @ RealVNC Ltd. > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > > > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > > > > > > > > Sent: 09 August 2005 17:27 > > > > > > > > To: James Weatherall; [email protected] > > > > > > > > Subject: RE: True color and extremely slow speed > > > > > > > > > > > > > > > > James: > > > > > > > > Yes, I wondered if that went anywhere. Attached > > > > > is the email I > > > > > > > > originally sent. I don't know if Fast user switching > > > > is on. I > > > > > > > > originally thought it was a VNC option, which I > > did not see. > > > > > > > > I'll look > > > > > > > > at it on the server. > > > > > > > > > > > > > > > > Thanks for responding to me. -Pat > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > > > From: James Weatherall [mailto:[EMAIL PROTECTED] > > > > > > > > Sent: Tuesday, August 09, 2005 11:14 AM > > > > > > > > To: Boland Pat-A19945; [email protected] > > > > > > > > Subject: RE: True color and extremely slow speed > > > > > > > > > > > > > > > > Pat, > > > > > > > > > > > > > > > > I'm afraid I can't find any record of you having > > asked this > > > > > > > question > > > > > > > > before, in our archives. > > > > > > > > > > > > > > > > Can you explain what you mean by "blank screen"? > > > > > > > > > > > > > > > > Are you using Fast User Switching and/or Remote Desktop > > > > > on the XP > > > > > > > > machine that is running server? > > > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > > > Wez @ RealVNC Ltd. > > > > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > > > > From: Boland Pat-A19945 [mailto:[EMAIL PROTECTED] > > > > > > > > > Sent: 09 August 2005 17:04 > > > > > > > > > To: James Weatherall; John Mao; [email protected] > > > > > > > > > Subject: RE: True color and extremely slow speed > > > > > > > > > > > > > > > > > > James: > > > > > > > > > I've asked this question before, but still have > > > > > > this lingering > > > > > > > > > problem. I am running VNC on and XP server. When I > > > > > > bring up the > > > > > > > > > viewer on either an XP desktop or Win2000 desktop I > > > > > get a blank > > > > > > > > > screen. > > > > > > > > > The connection goes through, but I just get a blank > > > > screen. > > > > > > > > > When I shut > > > > > > > > > down the VNC server side and bring it up > again, it works > > > > > > > fine, but > > > > > > > > > once I close the session, I can be assured of a blank > > > > > > > screen on the > > > > > > > > > next desktop connection. I would leave it on > > all the time > > > > > > > > but other > > > > > > > > > desktops have to use it as well. Since the > > server is 2000 > > > > > > > > miles away > > > > > > > > > shutting down and restarting the server side is not a > > > > > good work > > > > > > > > > around. > > > > > > > > > > > > > > > > > > Any suggestions? > > > > > > > > > > > > > > > > > > Thanks - Pat Boland _______________________________________________ VNC-List mailing list [email protected] To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list
