# Help - DVI signal from PC gets dropped by TV



## Otto (May 18, 2006)

Hi there,

I have a problem with my HTPC video signal. The connection goes like this:

ATI Radeon x600 DVI output --> MonoPrice 3x1 HDMI Switch --> Panasonic Plasma

From the video card to the switch, I'm using a DVI to DVI cable with a DVI to HDMI adapter at the switch end. From the switch to the TV I'm using an HDMI to HDMI cable.

I'm also switching a Denon DVD player and Dish Network DVR through the the MonoPrice HDMI switch, and they have no problems.

In general, the PC works OK -- I can use the TV as a monitor, watch DVDs, etc. However, sometimes when I turn on the TV and select the PC as the input, I will get no picture from the PC. I have to go to another PC in the house to remotely shutdown the HTPC. Once it comes back on, everything is fine between the PC and the TV. All connections are good, proper inputs are selected, etc. It's just that after a while (I don't know what "a while" really _is_, but let's just say a few hours).

If everything is working, I _am_ able to switch between the Dish Network signal and the PC, so it's not just a matter of switching to a different input and not being able to go back to the PC.

Any ideas? I'm not an HDMI/DVI expert, so I'm not sure what the problem is. I think there's some handshaking going on at each connection point, so I'm not sure what the point of failure is. Is it the PC, the switch or the TV?

I've ordered a new HDMI video card, as recommended here. The ATI I have now has been problematic, and ATI drivers are the worst I've seen. I've heard good things about the GeForce stuff, so hopefully it will help. It should arrive today or tomorrow.

So, any ideas on what could be the problem? 

Thanks!


----------



## Mike P. (Apr 6, 2007)

It sounds like a handshake issue. Have you tried turning on the PC before turning on the TV?


----------



## Otto (May 18, 2006)

Hi Mike,

If I have the TV on, and then turn on the PC, it's fine. The PC then remains on 24/7. At that time, I can then switch back and forth between Dish/PC/DVD and all is OK. 

The problem arises later in the day. Suppose I want to come home and watch something on the PC tonight -- that's when I have to reboot the PC. I don't even think that it has to be switched away from the PC. But when I come back in the evening it just won't display to the TV.


----------



## Mike P. (Apr 6, 2007)

""*sometimes when I turn on the TV and select the PC as the input, I will get no picture from the PC""*

Otto, If the TV is on and working with the dish or DVD, turn off the TV before you select the PC. If the problem is caused by the TV handshake, that should be a solution. I have the same issue with a Sony Bravia.


----------



## Otto (May 18, 2006)

Yeah, I've done that too. For example, the PC is selected at the HDMI switch, and the TV has "HDMI 1" as its input (the input to the TV itself never changes; I only use the one HDMI cable to the TV). Then, when I turn the TV on, still nothing. 

In fact, I could do something like this: watch PC on Monday night. Turn off the TV when I'm done, but the PC stays on. Come back on Tuesday night and turn on TV (PC is still on and HDMI switch is still on PC). No picture on TV with PC input.

I need to try to continue to narrow in and be 100% sure of these steps, but I'm pretty sure it's accurate in the way I'm describing it. I also plan to remove the switch from the path and see if it fixes the problem. New video card should also be here soon, and I really, really hope that solves the problem.

Thanks for the ideas! Keep 'em coming!


----------



## Mike P. (Apr 6, 2007)

When you say the PC is "on", do you mean no screensaver, no sleep mode and no hibernate?


----------



## Otto (May 18, 2006)

Right, no screensaver, no sleep, no hibernate. However, we commonly "Remote Desktop" from other PCs (to control audio only) and the screen simply goes blank. I think it also goes blank even if we are not using "Remote Desktop" -- but I'm not 100% on that; I rarely leave it on long enough to go blank. Thinking it over, I guess it's possible that we could consider a blank screen a "screensaver."

Thanks!


----------



## Mike P. (Apr 6, 2007)

Let us know what the results are when you eliminate the HDMI switch. I'm really curious to find out what the problem is here.


----------



## Otto (May 18, 2006)

Yeah, I'll work to reliably repeat it. If I can get it failing by using some known sequence in, say, one minute or so, then I should be able to narrow it down pretty quickly.


----------



## Otto (May 18, 2006)

Well, things had gotten A LOT better since installing this video card. I really thought things were fixed, as I had not received a "nothing" screen at all. Then, last night, I get a "nothing" screen. I go through the reboot process remotely, turn the PC off, then power back up. I get the BIOS screen and the "Windows" screen, but as soon as it goes to the main Windows login, it goes black. I can login remotely, and the PC is working fine, but I get nothing at the TV. Ahhhhhhhhhhhhhhhhhhhhh! What an annoyance!

I'll try to figure out what's going on with this card. Still, I'm convinced that the other card (ATI x600) was junk. No surprise: I have always had problem with ATI video cards.


----------



## Otto (May 18, 2006)

Fixed the GEForce card's output by uninstalling and reinstalling drivers. I got the latest from the website, so hopefully they've gotten than bug taken care of. Actually, I bet it was a lingering part of the ATI drivers that are still out to get me... :devil:


----------



## Mike P. (Apr 6, 2007)

At least things are getting better. Hopefully you'll get it all worked out.


----------



## Otto (May 18, 2006)

Hi there, Mike P and anyone else who might be able to help!

Still using the XFXForce 7600 GS card with HDMI output. Every once in a while, the video output will just disappear, and then I have to reinstall the drivers before it will work again. Tonight, in an effort to ensure that it's not "something else," I reinstalled Windows XP Media Center and then installed the drivers. I didn't install any other drivers or software. As soon as I switched to "Dish" on my Monoprice switch and then switched back to "PC" the video output no longer worked. The DELL and Windows "splash screens" show up (so I know the switch and cables are working) but once it comes to the time to get a mouse cursor and XP logon, I get nothing. 

At this point, I will have to reinstall the drivers again for it to work. Lame.

I have also taken the switch out of the equation, plugging the HDMI cable directly from the video card to the TV.

Now, imagine that I have everything working (drivers installed, display OK, etc.) and the video card is connected directly to the TV (i.e., no Monoprice HDMI switch). If I simply unplug the HDMI connection while the PC is on, it will cause this situation apparently 100% of the time. Yep, if the PC is on and working and I pull the HDMI cable it will cause me to have to reinstall the nVidia drivers before things work again at all. 

Also note that once this occurs, I cannot use the DVI or VGA (via DVI to VGA adapter) output of the card. I can't view anything on a regular old VGA CRT. It's like the video card isn't there.

Has anyone ever seen anything like this? It's driving me nuts and really precluding use of my HTPC. I have to reinstall drivers almost every day. Since I just did a fresh install and I didn't enable Remote Desktop, I can't quickly reinstall drivers and reboot from another PC. Think I'll reinstall Windows again rather than drag up an old CRT monitor, enable on-board video, etc.

I will say that XFXForce support has been pretty good, and the last thing that they suggested was a clean install of XP. I've submitted my results (as above) and will see what they say tomorrow...

AHHHHHHHHRRRRHGGGGGGGGGHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!

Please just work!!!!!!!!!!!!!!!!!


----------



## Mike P. (Apr 6, 2007)

Since you've narrowed down the possibilities, it sounds to me like this is a video card problem. Any chance of swapping the card out with another one?


----------



## Guest (Feb 5, 2008)

I have, I think, the same problem. The specs of my machine are:

Vista Ultimate 32
Intel Core 2 Duo E6750 / 2.66 GHz
2GB PC2-4200 DDR2 DIMM Memory (533) - had on shelf and plan to replace
GeForce 7600GS 256MB HDMI 400M DVI DDR2 PCI Express 
Auzentech HDA Digital X-plosion 7.1 DTS Sound Card 
Gigabyte GA-P35-DS3L
Zalman HD160B

I have the HTPC and a Comcast HD DVR connected to my AVR-1508 Dennon Receiver with HDMI cables. The Dennon is connected to a 50 inch Panasonic 720p plasma with a single HDMI cable. In theory, I should be able to use the receiver to switch this way. Every time I switch to the HTPC (always on, no sleep, so hibernate, no screen saver, plain blue background with no icons), I get a black screen. I can restart in safe mode, delete the Nvidia driver, restart and re-install the driver and it works fine… until I switch to the Comcast set top box and back to the HTPC… black screen again.
I figure that this was either (1) a hdmi handshake issue (2) the switching function of the Dennon (3) some vista corruption resulting from my ‘tuning’ and configuration attempts. I eliminated #2 by taking the Dennon out of the equation. The issue occurs if the HTPC is plugged directly into the TV.

My next step was to reinstall Vista and see if the problem still exists. Please post what the XFXForce tells you…

Andy


----------



## Otto (May 18, 2006)

Hi Andy,

Wow. Someone finally understands my problem. I sent the video card back to XFXForce. They said it tested fine, and they said they swapped my card anyway to help me troubleshoot. I can't verify that since I didn't write down the serial number, but let's just suppose it's true.

Can you do the same thing that I described above? Just have everything running and working, and unplug monitor cable from the video card. I think I described it above, but I've done it with the plasma TV as well as a flat panel analog PC monitor (DVI output -> DVI to VGA adapter -> VGA monitor). Same thing. Everytime I unplug it, I have to reinstall drivers.

The new video card I received from them does the same thing. 

I was using Windows MediaCenter, so I thought maybe that was the problem. I installed XP pro and have the same problem. I have tested this with no other hardware in the system, with fresh OS installs and the same thing happens everytime. 

So, what remains to be the culprit?

1. Motherboard
2. RAM
3. Hard drive
4. Power supply
5. Processor

I was most suspicious of the motherboard. Last night, I did some research, and I think I've decided to buy the same motherboard you've listed (the Gigabyte). However, before I do that, I'm going to test it on another system to which I have access (Dell Precision 390). I'm assuming it has a PCIx16 slot that I could use. I will see how that behaves.

Another reason that I'm suspicious of the motherboard is that I have problems with the original video card (some ATI junk). It's not as bad as the nVidia, but I do have to sleep->awake or reboot every once in a while. Also, I find the ATI drivers and software to be poor, so that's a constant source of annoyance (e.g., I can't resize my desktop at all right now because CCC won't execute. Never again with ATI for me!).

To find that you are having the same problem with the motherboard I thought I wanted it discouraging.

I think you should also contact XFXForce. Although we have not come to a resolution, I will say that their tech support has been very helpful. My ticket number is 124758, if you want to tell them to reference that. I will PM you the whole thread between them and me, and you can see what they came up with. 

If we can resolve this with the video card vendor, that would be great. I will be really bummed if I buy a new motherboard and it's the same thing.

Thanks and good luck!


----------



## Otto (May 18, 2006)

ahedberg said:


> I can restart in safe mode, delete the Nvidia driver, restart and re-install the driver and it works fine


Oh, I forgot to mention that you can probably skip the deleting the nVidia driver. I just reinstall the drivers and it works OK. I can also do this from a Remote Desktop session in order to skip the Safe Mode boot.


----------



## fibreKid (Apr 20, 2006)

Does anyone have a friend that has a different type of HDTV that they might allow you to connect your PC to? IT sure sounds like a handshake issue but maybe it's a brand of TV handshake issue? Who knows how it's wedging the SW/HW config...

-john


----------



## Otto (May 18, 2006)

For me, I used both the plasma and a regular Dell analog flat panel monitor. Same thing in both cases.


----------



## Guest (Feb 7, 2008)

Otto –

I have created a ticket with XFXForce yesterday and referenced this string. I will also try the direct connect / unplug idea, but won’t be home until tomorrow evening… I plan on doing this before and after a fresh Vista install and will post the results.
Thanks for sending the details from your support ticket. I haven’t had the chance to review yet, but will soon.
I don’t think it is any of the other items mentioned… My setup was working fine on my old planar plasma. I was, however, switching back/forth from digital to analog (DVI to RCA) – not digital to digital. Since then, I was trying to get a QAM signal with an Aver card, so I can’t be sure that process didn’t mess things up. I plan to try the direct disconnect on the old planar too… it doesn’t have HDMI… just a single DVI… so I can’t test the digital / digital. I happen to also have a 42” version on the Panasonic (same product family as mine) still in the box. I may try that too. I think that if the same thing doesn’t occur on the planar, it has to be either the handshake with Panasonic or a video driver issue. 
The two items that our setups have in common are the Panasonic TV and the card. My TV is model TH-50PC77U… what is yours? 
Otto, PM me your email. I don’t have enough posts on this site to get PM privs yet.
Andy


----------



## Otto (May 18, 2006)

Yeah, I still think it's some weird interaction between the drivers and the system. I sent them another note today, offering to send in my whole system for FA. I don't think that's going to happen at this time. They did verify that they swapped cards for me and that they tested the new one before sending it. I don't think that the video card is necessarily defective, but there's something going on with it...

My TV is the TH-58PE75U.

I'll drop you a PM as well. 

Thanks!


----------



## Guest (Feb 8, 2008)

I heard back from XFXForce... they wanted to check that I had the latest drives, Bios, etc... I replied back that I did... so the ball is back in thier court.

I tested the direct connect / disconnect and sure enough, the signal does not come back. I am going to borrow another card and see if that I can isolate it.

Andy


----------



## Otto (May 18, 2006)

Yep, I installed all the latest drivers for my BIOS as well and I continue to get the same failure

Keep pushing them. At this point, I'm thinking it's more to do with the drivers than anything else. If you remove all the drivers and just go in default VGA mode, you can plug and unplug the connection all day. As soon as you install the drivers (don't even change resolutions or anything else), and then unplug the device, you're dead. Sometimes I have to plug and unplug twice, but it always and quickly leads down the same path.

Ya know, when you install the driver package, it installs the "control panel" for the nVidia stuff. I wonder if one could divorce the actual drivers from the "control panel" and see if that sheds any more light.


----------



## Guest (Feb 8, 2008)

I called Panasonic... they said it was probably a cable... don't think I buy it.

Otto - when you restart your computer, do you get the bios splash screen and then nothing - or - nothing at all.

I get the bios screen.

Andy


----------



## Otto (May 18, 2006)

It's not the cable. it happens on the HDMI cable to the TV (using the HDMI output of the video card) and it also happens with the DVI output of the video card using a DVI to VGA adapter to a Dell VGA flat panel. Totally different cables, video card outputs, display devices, etc. This refers to the unplug->plug in test.

Yeah, when I have the failure, I get the BIOS screen and the blue DELL logo, but once it attempts to go to Windows high resolution, there is nothing at all. That tells me that the outputs are all working, the cables are working, the displays are working. 

DRIVERS - DRIVERS - DRIVERS!


----------



## Guest (Feb 13, 2008)

Otto - 

I changed the following setting on my tv and then reinstalled the drivers and have not had an issue for three days.

menu > setup > other adjustments > no signal shut off = no.

I still think it is a driver issue and something 'stuck' the last time I installed. I don't know if it will last. Can you see if you have the same setting on your TV?

Now, my remote stopped working .... argh!!!!!!

Andy

PS - no love from xfxforce yet.


----------



## Otto (May 18, 2006)

Hmmm. What if you unplug/plug in the cable?

XFXForce didn't say anything?


----------



## Guest (Feb 20, 2008)

I can plug and unplug to my hearts content... I rebuilt the machine last week end and the problem did not resurface. Do you have a simular setting?

I stopped trying to work with XFXforce, they didn't have much to say until I tried it on another HDMI TV (which I don't have). 

I still think it was a problem with the driver, and the reinstall finally took. We will see if it re-surfaces.


----------



## Otto (May 18, 2006)

Hmmm. I know my TV has an auto-off feature, but I'm not sure if I can control it. I'll have a look tonight (if I remember). But I think last time I did a fresh XP install, I was using a Dell analog flat panel, and it died as soon as I unplugged and plugged it back in (i.e., there was no TV in the loop such that the auto-off feature wouldn't matter). 

I think I'm going to buy the same motherboard you have and just build a new machine. One question about your motherboard -- do you know if it will output analog and digital audio at the same time? I really need that feature!

Thanks.


----------



## Guest (Feb 20, 2008)

I had both an auto-off and a no signal shut off, but if you are having issues on a monitor, that blows my theory out of the water. 

I don't know if the MB does both analog and digital, I am using a Xplosion card. Is there a quick way to tell? One thing to note is it does not have firewire...

Andy


----------



## Otto (May 18, 2006)

Hey Andy,

Not sure if there's an easy way to tell if it does analog and digital at the same time. I'd only suggest hooking it up and trying, but that can be a pain. Don't worry about it; I just figured that if you knew right off the bat, it would help me make the decision tonight.

Thanks.


----------



## Otto (May 18, 2006)

Hi Andy,

Is it possible that you have a Logitech wireless keyboard in your system? I bought the same motherboard that you have (Gigabyte GA-P35-DS3L) and I have the same problem with the video card (that motherboard _will_ do analog and digital audio out at the same time, btw). I was reading on the NVidia site, and they said a similar problem could occur if you have a Logitech camera installed, but I don't have one. I am using the Logitech DiNovo keyboard, though, and I'll try removing it from the system tonight. 

I can't believe that there is simply no end to this. I have replaced everything except the RAM, the processor and the drive. I believe more and more that this is a video driver problem.


----------



## tonyjover (Feb 1, 2008)

Hi all,

Just come to this thread late, so apologies if I've misunderstood along the way.

Are we saying that if you disconnect the PC Video Card's output and then reconnect it you have now lost the output and/or blue-screened the PC? If so, that's common to most modern video card drivers. It doesn't matter whether the diconnect is done manually (pulling the plug) or electronically (switching over using a switch).

There's no fix other than using the latest drivers (which probably won't be any better) and/or switching off the pc prior to disconnecting the video output.

Modern video card drivers simply don't like to see no monitor connected, and they either lock up or crash when that is the case. You really can't blame the card manufacturers; the cards are designed to be permanently connected to a monitor.

Regards,
Tony


----------



## Guest (Mar 4, 2008)

Otto - No logitech here. I have been using a wired keyboard... bought the microsoft verson, but it was junk.

I agree that it is a driver issue... Not to rub it in, but my problem has not resurfaced. As I write this, I am thinking I should take a snapshot of the OS drive when I get home, just in case it resurfaces.

I imagine that you completely reinstalled the OS if you have anew motherboard. When you rebuilt, did you have your PC connected to the Internet? Was the video card in? With Vista, the install will look at the MS Update site and download drivers for the device, which would then be over written when you installed the ones from XFXforce. Maybe there is some legacy from that. When I installed, I have the videocard in, but was not connected to the internet. Beyond that, all I can say is ***!

Andy


----------



## Otto (May 18, 2006)

Yep, reinstalled the OS multiple times between this motherboard and the last one. Used both XP Pro and MediaCenter. Not sure if I was connected to the Internet or not. I don't have Vista, though, and when I installed XP, it was SP1, and I had to upgrade to SP2. Previously, I used "Driver Cleaner" or something like that, which they (XFXForce) said would remove all drivers. Same problem.

I'm talking with NVidia directly about their drivers since XFXForce just directs me to the NVidia site for driver downloads. Therefore, I think it's NVidia's problem to talk about drivers.

Thanks again.


----------



## Guest (Mar 12, 2008)

Hello!
I have the same problem with my TV.
I have an HTPC with ATI X1250 (also tried ATI HD2600pro) and the picture dissapear when i turn off the TV and back on.
The only thing that helps is to unplug HDMI cable and set it back in, or restart the HTPC or last to set the PC in sleep and back on. (I can set the PC in sleep for 0,1 sec and back on for the picture to come back on).
Here in Sweden there are more people who has the same problem, as i can se most of them with ATI Graphic cards.


----------



## Otto (May 18, 2006)

Hi Kristain, and welcome to the Shack.

I think that's a slightly different problem. I also have an ATI x600 video card, and I'm using it because I have so many problems with the NVidia 7600GS card. The ATI card only sometimes loses sync for me, so it's the much lesser of two evil. Plus, as you say, it will come back if you sleep and wake the system, which (while a pain) is easy to do.

Anyway, I've also been trying to fix that problem. The latest thing I've tried is to allow "clone" mode in the ATI Catalyst Control Center software, but make sure that my primary monitor is in the "Monitor 1" position. I haven't seen a problem with that mode yet (a day or two), so I'm not sure it's the answer. However, it definitely resolved a problem I had in which PowerDVD was displaying a blank picture.

Anyway, good luck. I can't seem to beat this thing myself...


----------

