Topic: Help needed re 42LZ80 to pc problem.

[wunder9]

Few days ago I got a Panasonic 42LZ80 from TW-Pioneer. I only use a pc (with nvidia 8800gt gpu) hooked to the LZ80 via dvi-hdmi. Anyway, after several trips to the shop and testing several units, we isolated the problem was being caused by my pc. Every unit that was connected to my pc would have power-on or standby power mode problems. My pc was causing the tv not to turn on. This happens about 95% of the time. Once disconnected from the pc, all the tv's worked in perfect order. No difference if my pc was on or off, once attached to the tv, the tv would would not turn on.

The logical solution was to turn on the tv before plugging my pc to hdmi-1 input. This worked perfectly. I installed a coupler between the tv's hdmi-hdmi cable & pc's dvi-hdmi cable to avoid damage to the tv input if I need to do this plug-unplug very often.

Would anybody have a theory why my pc affects the tv's standby mode & power-on?

I'm considering getting an hdmi switcher to replace the coupler. But I have no idea if that would work.

[Clondalkin]

Copied from fixya.com

I have my computer connected (dvi to hdmi) to my tv. Recently I upgraded my computer to an amd dual core and a geforce 6500 video card. Now the tv won't turn on (flashing led light - 3 times). It will turn on when I disconnect the hdmi from the back of the TV, or disconnect the DVI from the back of the computer. Weird thing is, once the TV is on, I can connect it to the computer and use it just fine. Any ideas?
Comments:
Dec 08, 2008- Thanks for the note. Just in case anyone else has this problem, here is the reply from Panasonic:

Thank you for your e-mail. Our factory engineers have advised that the HDMI 1 & HDMI 2 inputs at the rear, unlike the HDMI 3 input, do not have the equalizer/buffer circuit between the HDMI input and the HDMI receiver. They are dedicated HDMI ports for Audio/Video components (BluRay, Satellite boxes, Cable boxes, PVR). Without the equalizer/buffer circuit, the TV will not display picture and/or sound. One can either use the HDMI 3 input or there is an Extender Boost adaptor available from GE, model 22703, that one can connect between the rear HDMI input and a PC, using another HDMI cable (the adaptor is female on both ends).

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have you tested VGA connection?

[paolorenzo]

Galing talaga ni sir Allan...  Super tech support.   

[tailhook]

it happened to me also. my 32lx77 connected via hdmi (using my onboard video) would display garbled/distorted images if i turn on and off the tv while my pc was also turned on. the solution was to turn off/restart the pc while the tv was on. I recall when this error occurs, the 'on' light would turn orange color, instead of the usual green.
when i upgraded to a discrete video card (radeon hd2600xt) and hooked up my tv using hdmi, i no longer encountered the same errors. i could switch the tv on and off and have no problems with the garbled or distorted images.
this leads me to conclude that the error might be attributable to the hdcp kicking in as implemented by the tv, thus, the garbled images but with sound. the radeon implements hdcp correctly thats why no longer encountered errors.(my noobie theory)  oh, by the way, my motherboard is asrock alivenf720p rev. 2, with the geforce 7 series (nv44) integrated video.

[wunder9]

Thanks for the replies. AVS forum threads suggest the GE part 22703 extension adapter or Monoprice 2849 active repeater extender should do the trick. Hdmi switcher may work also.

I'm surprised that similar problems are common with Pana plasma/htpc users in the US.

[The Game]

I have this same problem for my 42lz80.... another solution is if your using an extended desktop for your lcd tv, you can just turn it off first in the settings panel (or nvidia control panel for nvidia cards)... its much easier that way and you won't need to restart your pc or unplug anything everytime...

[tailhook]

^ - thats right! as a simple solution, i would just right click on the desktop and disable the extended monitor (my lcd), apply the settings and then re-enable it again. that would allow me to use my lcd without restarting. it seems that the problem is on the part of the nvidia graphic cards. doesnt happen to my radeon hd2600xt and i can switch on and off my tv (now plasma 42c10) without any problems. so.... change your graphic card. hehehe

[boybi]

Can anybody else confirm that by using Radeon based graphics cards, this problem doesn't exist?