S-video jack detects opposite.

bryanlacksfocus · #1 November 17th, 2007, 12:20 PM

Hi, my PowerBook has an s-video cable that has somehow gotten confused and tells my computer that there's a display hooked up through the s-video when there isn't and there isn't one when there is. I generally keep it hooked up to my TV when at home and when I want to watch something from my computer on the TV, I have to unplug the cable click Detect Displays and then re-plug it in. What is most annoying though is that there is no way to turn off the additional displays when I am using my laptop away from my TV (say, at work or a coffeeshop) and often the cursor and certain windows disappear off the screen.

I reformatted the drive and reinstalled the OS, hoping it might be software-related. I took it over to the Genius Bar, but their guess was that it is a hardware problem that would require replacing the video card. The PowerBook is a G4 15in. Aluminum 1.25GHz running Tiger.

I was wondering:
1. Has anyone ever heard of this happening?
2. Is there a way to fix it besides expensive hardware replacement?
3. Do you know of any quick-fixes — e.g., third-party apps that allow you to turn on and off displays individually rather than have them be automatically detected, or even a dummy s-video plug that sends a signal to the computer that it is attached to a video display?

Thanks for any help!
Bryan Morrison

bryanlacksfocus · #2 November 21st, 2007, 09:21 PM

Nobody has any idea?

Satcomer · #3 November 22nd, 2007, 08:59 AM

Disconnect every external thing from the PowerBook and then Reset your Pram. This may help.

Hippo Man · #4 November 24th, 2007, 12:50 PM

Quote:

Originally Posted by Satcomer

Disconnect every external thing from the PowerBook and then Reset your Pram. This may help.

The "Reset your Pram" link points to a non-existent page. Could someone suggest the correct target for this link?

Thanks,

.

icemanjc · #5 November 24th, 2007, 01:37 PM

Here you go. How to reset pram.

Hippo Man · #6 November 24th, 2007, 01:52 PM

Thanks!

.

bryanlacksfocus · #7 November 24th, 2007, 11:30 PM

Thanks for the suggestion, Satcomer, Hippo Man & icemanjc. I just tried resetting the PRAM (holding cmd+option+p+r during start-up til it dings a second time). Unfortunately, there's no change.

Can anyone think of anything else?

bryanlacksfocus · #8 February 22nd, 2008, 09:55 PM

I have not found a real solution to this problem, but if anyone out there is experiencing the same thing, this is what I figured out...

Take the RCA-to-S-video adapter that came with your Mac (or get a new one) and plug that into the defective S-video port. To the RCA end connect an F-to-Phono Adapter (I got this one) and to that screw on a terminating resistor (I got this one). If you detect displays (or wake from sleep) with this setup connected, your computer thinks it's connected to a TV and--due to the confused video hardware--registers only one display.

Yes, you will have to have this silly, little pig-tail hanging off your computer all the time, but it beats having an imaginary display to get windows and cursors lost in.

If anyone has any other suggestions, though, like display tweak apps, I would gladly welcome them.

B