VGA / DVI Connectivity

your projector has a native resoluton of 1280x720@60HZ.
Are you sending720p as the output resolution from your laptop over HDMI? Is your PC desktop resolution set to 1280x720?

Well 1, is it a DVI-I cable? Usually DVI cables are DVI-D, which is why you wouldn't get anything from the VGA adapter.

As far as HDMI goes, have you ever tried the DVI cable before now? It's possible it's bad. It's also possible the HDMI adapter is bad.

Do you have a another cable/adapter you could try. eg could you borrow a DVI cable off one of your PC monitors or something and hook it up temporarily to see if that shows up correctly?

I have never even heard of a DVI-I cable. I am not aware of any laptops that don't have a VGA output port and yes many of them also have a DVI or HDMI output port.
Are you running the laptop screen and the PJ in extended desktop or clone display mode?

Dunno if I will be of any help, but I own the little brother BenQ PE7800. The only main difference is the DLP resolution. Chassis should be the same.

Your PJ has a DVI-I socket. You know it's DVI-I because one of the holes in the socket is actually a "slot", and the 4 pin holes surrounding the slot carries the VGA signal.

There are two ways to send VGA top the PJ: 1) via the 5 BNC connectors; 2) vis the DVI-I connector. You have to choose the correct "input" within the PJ's menu system.

Of course, if the cable running to the PJ does not have a slotted pin, the it's a DVD-D cable (i.e. no analog) and neither VGA option will work.

-T

Using Extended desktop mode you need to set the reolution going to the PJ to 1280x720 and the resolution going to laptop to it's native resolution.
With no cable conntedte to ther PJ you may be able to get a higher resolution on the laptop screen and/or you may be able to get a 16:9 aspect ratio to display if your laptop screen is not a 16:9 screen. If you can do this for the extended mode setting for the laptop.
When you tried a VGA to DVI adapter the VGA signal was being to the digital pins of the DVI connection and not to the 4 analog pins.
DVI-I cables that connect both the 2 digital pins and the 4 analog pins are available but AFAIK you have to order then from one of the cable companies.
What make/model laptop do you have?

When I installed my PJ in NOV 2004, I recall seeing DVD-I cables from monoprice, but I could have a false memory. In any event, if your DVI cable is truly a DVI-D, then the connectors attached to the cable should not have the slotted pin... I am assuming the cable maker would not attach a DVI-I connector to a DVI-D cable. But I could be wrong.

My final idea... assuming the cable is DVI-I, on the projector end attach a DVI-to-VGA, and then a VGA-to-5BNC (also called a VGA breakout cable). I use VGA, but use the BNC connectors.



I do not see how that is possible. A DVI connector, if it can carry analog signals, has to carry the analog signal on the analog pins. See here for the pin out. It cannot put analog on the digital pins... would that not be in violation of the spec?

-T

Scroll down the following link and you find both single link and dual link DVI-I cables;

http://www.pacificcable.com/More_Pag...I-I-Cable.html

In acutality when the analog pins are being used for VGA they also have to use a couple of the digital pins also since VGA requires more then 4 wires in order to support the VGA sync sigal. When used for YPrPb component then 4 pins is enough.

jjb94941,

That problem might be related to an EDID issue. The model is correctly identified, but not the possible resolutions.

You may need to google "EDID windows 7 BENQ 8700" to determine if that is the issue.

-T