Help - DVI signal from PC gets dropped by TV

[Otto]

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.]

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

[Otto]

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.]

""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]

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.]

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

[Otto]

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.]

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]

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]

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.