Difficulty with projectors!

I have run a BenQ projector from a MacBook successfully for some time but suddenly the projector failed to recognize a signal. Replacing Apple's video to VGA adaptor made no difference but upgrading the VGA-VGA cable to SVGA-SVGA solved the problem. A friend has recently suffered to same failure and the same solution also proved successful.

We don't know the actual cause but it does appear that many VGA-VGA cables are not capable of carrying the 1024 x 768 resolution required or that constant unreeling and re-reeling damages their cores enough to cause failure.

I would now never leave home without a spare cable.

Thank you John, cable failure is an interesting possibility. It is a bit puzzling however that my recent problems occurred on two different projectors, each with its own cable. But I'll try to find an alternative cable to test this.

Denis

I agree, it is puzzling but I have experience of two failures and each was corrected by a cable replacement. I cannot emphasize too strongly that the replacement cables were of a higher quality than those provided with the projectors. The actual cause remains unknown. If a replacement cable solves your problem, and for both machines, I will appreciate a report!

I add that I also run a Macpro that drives the projector without problems but it has always used an SVGA quality cable.

I have the same problem.

I am using MBP (2007) with Snow Leopard installed. I am currently on a clients site providing some training. Using an Epson projector (mounted in the ceiling, cannot get the model number).

Using a DVI to VGA cable.

The projector does not recognise a signal from the MBP, and the MBP does not show anything in display preferences other than display and color tabs.

Detect Displays briefly allows a "blip" in the projector display, but then it returns to previous MO (no signal).

A slight difference in this case, I am using VMWARE to project some Windows software. I thought it may be Windows issue but all seems fine there. Just to confirm OSX is the native OS and Windows is running as a VM.

This worked fine on Day 1, but I have not been able to get it to work at all on day 2 no matter what combinations of turning on/off, connection time, resolution I have tried.

Any other suggestions greatly appreciated.

I do not have installation media with me.

My guess is that you will need to find out what model of projector is involved, Ptibbs, and provide some more info about its current settings, before people can give you much help (try asking the "clients". Generally someone local will know what sort of projector it is, even if it was just the "purchasing officer" and any local IT staff, of course, will be tickled pink being asked for help by an "outsider".)

But surely it is very easy for you to clarify whether using Windows through VM is making any difference to your own situation? What happens when you hook it up simply while running OSX?

Pretty clearly, too, if it all worked fine on "day 1" as you say, but doesn't now, either someone has changed the settings on the projector in the interim, you have changed settings on your MBP, or a cable or adaptor has failed.

Cheers

Rod

I regret I cannot add anything other than provide the information I've already given based on practical experience. I do not know the real cause of the problem but two failures have both been corrected by replacing the VGA cable with one of higher quality. No faults have been found in hardware or software. However there have been worrying inconsistencies: Two MacBooks worked with one cable and two did not and the same cable worked with a television's VGA input.

Not enough seems to be known (perhaps published?) about matching between digital equipment, nor do we know what variations are permitted in the video outputs of various models of even same computer. In my opinion what is desperately needed is a competent electronics engineer experienced in 'matching' to look at this properly. Operating system software does not seem to be a factor.

What little evidence we have points to the characteristics of cables deteriorating with use (reeling and unreeling), possibly coupled with barely adequate quality in the first place resulting in a decrease in signal reaching the projector. But I am not able to measure this and will not be surprised if I'm proved wrong. However, the first thing to try is to replace the cable with one of higher quality. Do let me know how you get on.

I tried another cable, that did not work.

I dont think any projector changes were made, if they were I reset the projector several times anyway.

I did not make any changes to my MBP configuration, but that raises the question of configuration of the graphics card. Other than in display preferences where could this be done?

Hi,

I finally had time to run more tests. I used a third projector. Same problem as with the first two: I can only use mirroring, the max resolution is 1024 x 768 at a refresh rate of 90 Hz. Lower refresh rates work, but starting with 96 Hz, this particular projector does not work.

I tried a second cable: no difference. I tried a second DVI-VGA adaptor: no difference.

Since I never had difficulties connecting until sometimes this summer, never had a difficulty using monitors NOT in mirror mode, and since after a period of approx. August until November I did not use projectors, but since November the three I have tried at work no longer work except with the settings above, I am tempted to conclude that the problem is not with the projectors (3 failed to connect "as before"), nor the cable (tried 2) or the DVI-VGA adaptor (tried 2). What changed since July: my OS (moved to Snow Leopard) and my mother board (changed under Apple Care).

It is mystifying that there was one successful connection at a congress in November. However, I can't be sure I did not have to use mirror mode to get it to work, so it weighs less in my conclusion.

Unless others have noticed a degradation when upgrading to Snow Leopard, I'll be calling Apple Care soon!

Denis

Hi Denis,

for what it is worth I can successfully use my own MBP in "screen spanning" (ie not mirroring) mode with an overhead projector under Snow Leopard.

I know it sounds silly, but have you tried changing the order of doing things when connecting to the projector? Having the projector turned on before connecting? Or shutting down the computer, connecting the projector, turning on the latter and then booting the computer? Or the opposite? etc etc.


I have seen external displays behave differently with different "start-up order" in the past.

Another thought, painful though it may be, could be to try a clean OS installation (perhaps on an external drive) to see if this makes any difference. Perhaps even simply establishing a new user account?

Cheers

Rod

I am also having trouble with a projector (I am not sure what type it is, b/c its in my classroom). I have 2 macbook pros, one running 10.5, one running 10.6. When I plug my Macbook Pro running 10.5, with a digital out to VGA in, the projector works perfectly fine. When I plug in the Macbook pro running 10.6, the projector does not display anything. This model has the new video out, and I have to use 2 adapters to get to VGA in. It strikes me that there is a software incompatibility here, because I have used the cords with an external hd monitor and they have worked fine.

dan,

If you are trying to use a mini-display to DVI adaptor coupled to the DVI to VGA adaptor you use with your older MBP it simply won't work. You have to use a single mini display to VGA adaptor with the current MBPs. (I've run into this issue myself)

Cheers

Rod

Has anyone found a solution for this problem?

I have a 2006 MBP and have been connecting it to projectors without problems for years. Sometime after I installed Snow Leopard, I stopped being able to connect to projectors while other people in my lab with newer laptops (also running Snow Leopard) don't have problems. If it matters, I'm trying to connect to an Epson EX50, but I've had problems with two other projectors. I've also presented from all of these projectors many times in the past two years, but none have worked recently (2 to 3 months).

I can connect to my TV using a DVI to HDMI cable and also my monitor works fine via DVI. My problem sounds similar to reports here so I was wondering if anyone has a solution.

Thanks.
Kimo

Wow! I just posted a question about the same problem. I'm a consultant and am ALWAYS using my projector. Today was a big nothing, an embarrassment, and cost me $$$. I'm an electrical engineer and well versed with computers and could find a fix on the spot. Came home and then had issues with my external monitor.

QUESTION... has anyone noticed the issue being more prevalent while using battery power vs. charging adaptor?

After more testing, I'm fairly confident my problem is a hardware failure. I partitioned my drive and installed Leopard. With the fresh install, I get an image from the projector but it is distorted with noisy lines and discoloration. It is also unstable - when I move windows around the projector loses the signal. I have tried two VGA cables and two DVI to VGA adapters. The projector works fine with other computers and the laptop works fine with digital displays (TV and monitor).

I guess I can't know if Snow Leopard burned out my GPU or if it's just a coincidence. It's an old laptop so things are bound to fail at some point.

Hi, wow... SAME PROBLEM! I have just bought acer h5360 dlp projector and connect it to my macbook pro witl SL 10.6.2. At first time all works but I saw some noise and lines. I try to change the resolution and now I am not able to connect the projector anymore. But the most strange thing is when I connect my macbook to my dektop lcd it now still produces this strange color noise and lines. And at my lcd television is this the same. But two months ago I connect my macbook to my lcd WITHOUT any problems and noises! I think there must be some problem with software update. Finally: 1) Why noise and lines? 2) What about projector? Is there any final solution?

The only good thing is - if I am not the only one with noise problem - I dont have to buy my new minidisplayport-dvi reduction and dvi hdmi cable....


aggggggggrrrhhh Apple please HELP US!