VGA output - no signal or image

Unfortunately, from the troubleshooting steps outlined in your post, it sounds like a bad vga port on your machine, But you might want to try going into system preferences with the display hooked up and select the "Displays" icon and click "Detect Displays" button make sure the heading bar at the top of the window you have open does not say Color LCD, this shows the properties of the laptop screen,it should say the name of the monitor you have. check the box next to "show modes recommended by display" and select a resolution and refresh rate from the list 1024x768 60Hz is the usual standard supported by most CRT monitors

I have a similar problem.

I connected my Mac to the external DVI monitor and it worked perfectly the first time. After a while, it went to sleep and after that, the external mon received no signal, although its model name can be displayed in my LCD side (mirror).

After that, I connect my Mac to a VGA projector and it worked perfectly. Still, the DVI problem remained.

Will try to zip the PRAM later today and see if it helps.

Connect to the HP 2025 (1600x1200): Fail

Connect to Apple Cinema Display: OK

Although the HP 2025 has no display on it (it went to sleep), it's info (supported resolution and model name) could be obtained by the Mac.

Since I have use the DVI on my LCD monitor for I while, I will plug-in a Video card with DVI and see the result. (For the VGA for PC, it works perfectly).

I have a similar problem with my 867 powerbook too (see my seperate post on the matter). Only with me the VGA comes out blue, the S-Video output doesn't work at all and when connected to another monitor and you plug in the power adapter, the adapter starts clicking and interfering with the display. It has been diagnosed as needing a new DC board, power adapter and logic board coming out around the £550 mark!!

I am having the same problem. At my office I have a 20inch Cinema Display and the DVI adapter works perfectly. At home I have a Sharp projector. I used to connect my iBook G4 to the projector without a problem. Now when I hook up my brand new 12inch Powerbook G4 my projector does not find the signal.

I have tried hooking it up with both the DVI and VGA adapters, but still no signal is being received from the projector. The computer sees the projector and correctly identifies it in my display preferences, but still no image.

Has anyone had any success with solving this problem? Please help.

It is looking as though my machine may be suffering from the same problem. My Dell monitor works fine on my PC and my Mac Cube but not when I use the mini-DVI to VGA adaptor to connect it to my PowerBook. See my posting on driving an external monitor. Either the adaptor or my PB is duff.

Fortunately my PowerBook is just in warranty, so doubtless I shall be listening to Vivaldi and drumming my fingers on the desk at 8 a.m. tomorrow.

Ian.
--

Has anyone found out the cause of the problem or a solution??

I used to have an iBook and an older G4 12" PB that I used with my PLUS projector - no problem at all. My current PB is a 1.33MHz with a miniDVI video out port (the other two were VGA). The projector cannot detect a signal from the PB, even though the PB detects the projector connected to it (DISPLAY).

HElp! I need a solution quick as I will be giving a presentation using my PB very soon.

Rob

I had exactly the same problem when connecting my HP SB21 mini projector: "no video signal detected" while the PB detects the projector as being a HP SB21. After having been playing with Apple notebooks from family (who all have different output connectors for this purpose) I found my HP SB21 working perfectly on their Apple PC's. This confused (and annoyed) me very much.
Finally I found the secret: first connect the short Apple special connection cable to the PowerBook and wait for the screen turning black and coming back; than switch-on the projector and connect the projector extention cable to the projector; finally make the connection between the two cables (serial to serial). In my case this tuned out to be succesfull. The PB is not recognizing the projector anymore, but instead indicates to see the projector as a VGA screen. Any other sequence in connecting the PB with the projector fails. (The PB detects the fact that the short Apple cable is connected; it looks like that a same effect takes place at the projector side when connecting the extention cable to the projector.)
Give it a try; maybe this works for you as well.

Frank

Hi Frank

Thanks for taking the trouble to reply. I thought this thread had gone dead, like my projector connection!

Well, I've been running around doing all kinds of things and I found a solution - perhaps totally by chance.

I went to confer with a 'video guru' at my local Apple retailer. He reckoned that my PB was sending out the video signal 'too fast' (faster processor than previous iBook and PB) so the projector could not pick up the signal. He advised me to try to reduce the resolution to 800x600 and also use the lowest possible refresh rate. Well, that sounded plausible.

But on the way home, I stopped by at a computer accessories store to buy a replacement VGA-VGA cable to connect my PB to the projector; the original one is a little short. I was intrigued to find that this was labelled as a 'SVGA' cable, although externally it looks just like a common garden VGA cable.

When I got home and plugged it all together - without any thought about sequence of connection or resolution - it worked straight away.

So how do you answer that! Still, I'm keeping a record of your instructions, in case I had inadvertently done that. Well, see next time.

Cheers.

Robert

I have a problem connecting a PowerBook G4 12" DVI to a video conference system from Tandberg. It is no problem with older PowerBooks with only a VGA port. I get the problem when the computer has a mini-DVI port. When I connect this computer to the system and chose "Detect displays" the computer sense there is something connected to the port and names this screen "Calypso". The response I get from the Tandberg system is that it doesn't support this kind of VGA format. After some trial and error I found a solution to this problem. By only connecting the short mini-DVI-I to VGA cable and a small VGA-amplifier and then chose "Detect displays" the computer seems to send out the right signal. The new display is named "VGA-screen". If a now connect the cable from the Tandberg system to the amplifier the system recognize the VGA-signal.

Is there anybody who knows why this problem occur and are there different VGA-formats?

Hi Tote

Sounds like exactly the same problem I was having. There is definitely something about the mini-DVI that does that connect comfortably to most projector systems out there, as compared to the VGA in the older 12" powerbook/iBooks. It's a pity that we cannot get an official explanation from Apple. All we have are various users and 'experts' opinions.

What is a "VGA-amplifier"??

I thought my own problems were solved by a new cable (see previous message), but when I went to give a lecture last week I was unable get my PB to project through the projector system in the lecture room. I forgot to try Frank Balk's (see previous message) sequence of connecting up.

The strange thing is with my new "SVGA" cable I can connect my PB to my own projector (Plus) using the miniDVI-VGA adapter without using any specific sequence. I will have to try it with a different projector...without the pressure of having to give a lecture in 5 minutes time!!

In summary, yes I have same problem with my PB; no, I don't know the solution - there may be several, and I don't know about VGA formats.

Rob

Hi Robert,
If there is a too long distance between your computer and the projector the picture could be of poor quality due to different kind of interferences. One way to solve this is to amplify the signal. I am using an amplifier from a German company TLS Communication, which is called SignalManager 500. You can find more information at this place http://www.tls-gmbh.com/index.php?locale=2 .

I agree with you that an explanation from Apple about this problem would be good. I can imagine how frustrating it is having a whole audience looking at you when you are trying to connect to the projector. Additionally, it isn't any good publicity for Apple and its computers.

Best regards
Totte

I had to unplug the power cord from my hp 2025 to get it starting again with my powerbook. It did still work with the other computer I have connected to that screen though.