Poor PC Image Quality - Onkyo TX-SR604 and Mitsubishi HD1000U and PC



I recently replaced my receiver with an Onkyo TX-SR604 which has HDMI switching and after connecting the new receiver to my projector and PC, I'm getting really poor image quality.

I've connected the PC to the receiver's HDMI Input #1 (using a 10' 24 AWG DVI to HDMI cable from Monoprice) and connected the PJ to the receiver's HDMI Output #1 (using a 35' HDMI to HDMI cable of 24 AWG from MonoPrice).

I'm getting a display which is pretty poor in quality with a resolution set at 1280x720 (the native resolution of the PJ). The Windows desktop has text which is slightly broken up, legible, but not clear by any stretch. It kind of seems as though a non-native resolution is being displayed.

I'm REALLY new to PJs and HDMI, but I believe the receiver has poorly implemented HDMI swithching; the combined use of a 10' foot DVI to HDMI cable (PC to receiver) plus a 35' DVI to HDMI cable (receiver to PJ) is degrading the signal; and/or, I've got something connected incorrectly.

As a side note...I had the PC and PJ hooked directly up via the aforementioned 35' DVI to HDMI cable and the IQ was very good with a resolution of 1280x720.

Also, movies from a DVD player through the receiver (via composite video) to a standard 32 tv look very good and movies from the same DVD player through the receiver (via a 35' component video cable) to the PJ seem to look good.

The PC has an ATI X800XT AIW video card with the desktop set to a resolution of 1280x720 with 32 bit color. In WinXP Pro under Settings, Advanced, Monitor Tab, the receiver is identified correctly as a SR604 which apparently has a maximum resolution of 1940x1080 (or something similarly high)? I didn't know that receivers have resolution settings?

Anyone got any ideas what I'm doing incorrectly or does my new receiver just suck with respect to HDMI implementation? Do I need a hardware driver for my PC/receiver?

Thanks for any suggestions.



Novice Member
hmm..could be a number of issues....

try setting the computer up through the reciever to the PJ using a couple of short HDMI cable.....I know it probably means a lot of faffing around moving kit, but at least it'll rule out the distance thing first......if the problem still exists then its quite possible the receiver is introducing some noise for some reason....

sadly i cannot help very much here because i still dont use HDMI other than when i had a direct DVD player to PJ connection (not anymore, cable got yanked and torn :( )...

if you dont get much more response here, post again and i'll move the thread to another forum section where perhaps someone might have more ideas....either Projectors or Entertainment PC's i would imagine....anyhow, given this is a slightly more exotic problem than a lot of people on here will get, its probably best to give it a couple days first in this section just in case the right person hasnt logged in yet ;)


Thanks Knyght_byte...I'm bummed about this issue.

As a side note, I called Onkyo technical support today and the rep indicated he's heard of no problems like mine. It doesn't sound like too many peeps use a receiver, PJ and a PC though. I asked him if he thought it could be the cables and he said peeps were using 60' HDMI cables to PJs with no image issues. I also asked the Onkyo rep if "more expensive" Onkyo receivers use a "better" HDMI switch and he said they use the same switches.

I also used another PC hoping my issue may be related to ATI video cards/drivers, but I had the exact same IQ with another PC which has a nVidia 7800GT card.

Based on the above, I think the Onkyo TX-SR604 does NOT like to play nice with PCs.

I've got a friend with a 10' HDMI to HDMI cable and I'm going to borrow it and see if it helps. Going from 2 35' cables (HDMI to HDMI and DVI to HDMI) to 1 35' (HDMI to HDMI) and 1 10' (DVI to HDMI) made no difference at all to the IQ.


Okay peeps...I'm REALLY running out of ideas here. The Onkyo service rep mentioned the possibility of there being a HDCP issue, but quickly said it shouldn't be the cause of my image quality issue.

I don't know a lot about HDCP, but is is possible my HDCP compliant Onkyo receiver is "down-converting" my video resolution (1280x720) from my non-compliant PC's video card into a lessor resolution and then sending the reduced resolution image to my PJ?

The image quality of my PC-receiver-PJ really looks like it's a "resolution"

Here's a thread regarding Onkyo and HDCP which is UNRELATED to projectors and PCs but hey, I'm getting desparate here for a solution;)

"That's strange. Please try more output format from the MediaBox to check if it's resolution related.

On the other hand, we tested a Onkyo TX-SR803 AV amp which has a 2-in 1-out HDMI section. We found that MediaBox HDMI input to the Onkyo and the Onkyo HDMI output is HDCP protected! The MediaBox HDMI output has NO HDCP signal and the Onkyo actually adds HDCP to it's HDMI output no matter the input source! Hence we can't display the MediaBox picture on a normal PC LCD monitor (which has no HDCP support) via the Onkyo HDMI switching!

Pixel Magic Support."

Based on the above...I'm guessing a HDCP signal is either "passed on" to a display, or it isn't (i.e., no picture would be displayed verses a "degraded" resolution).



Did you find a fix for your problem? I want to buy the 604 and connect it via hdmi to my windows media center pc's dvi video card but am scared I am going to run into the same problem. Has anyone else out there connected a hdmi switching capable reciever to a pc video card successfully? Also, is there an info funtion on your projector to tell you what resolution is being displayed?




Standard Member
whats your resolutions set to on the projector and pc?


I have the Onkyo 604E connected to my PC using HDMI<>DVI and my panasonic PTAE700 projector connected to the Onkyo using a 12M HDMI from Joe Ferrand.

It works fine and I have none of the issues listed. I use it with XP and My HTPC software to play DVD's. I am using an ATI9600 set to 1280x720

The only thing I got was an occasional HDCP confusion when I switch from my Xbox 360 to the PC throught he Onkyo, not sure why this is, but I need to power off/on the projector. This has happened to me twice so I am not too concerned and resulted in the picture dissapearing every 30 secs.

What kind of display are you using, if it is not native 1280x720 then it will try to resolve the mapping internally, also double check your video card is not setting itself to it's highest resolution. Mine did that till I disabled it, the projector was advertising that it could support a resolution much higher so the card was defaulting and it looked crap.

Not sure this helps, but I am very happy with mine.


I've been messing around with the Onkyo/PJ/PC using various cables and resolutions for some time now and when using the PC have found it looks best at a resolution of 1024x768. Many peeps kept saying to use the native resolution of the PJ which is 1280x720, but for some reason the IQ looks better to me at 1024x768 with the PC. To top it all, using a resolution of 1024x768 and a VGA cable seems to looks better than a resolution of 1280x720 and HDMI:HDMI or DVI:HDMI cables. The PJ is putting out a 720P signal for both resolutions. I can't figure it out, but I don't think the Onkyo or cables are responsible. More like a resolution issue with respect to the PJ and PC.

The PJ still looks great with movies and games so I can live with the somewhat grainy IQ while using the PC/PJ and looking at text. I don't plan on "surfing" or word processing on a 92" screen so I've given up on it for now and have decided it looks good enough till the 1080P PJs come down in price (like down $2k) and hopefully the IQ will be much better;)

Overall, I really love using the PJ and having a really big screen (compared to TVs at the moment). My cost has risen a LOT though since I had to buy a new receiver and tonight I ordered a set of Mirage Omnistat speakers (5 satellites and a 10" sub for $620.00 shipped). With the stereo upgrade (receiver and speakers) and PJ system, I've spent about $2,300.00 (please don't mention this to my wife;).

Thanks for all your opinions and advice.



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