Odd external monitor problem on Windows Vista?

By acaseltik ·
I have a really odd problem with my external monitor.

To keep it as short but as informative as possible: I connect my monitor. It goes to power saving mode. I go to the Windows mobility center, click "Connect display" and it connects my monitor. The problem is that the external monitor is still blank. I try with the Fn + F5 combination to make my external monitor my main display, still nothing. I go to the ATI catalyst control panel and I see that my monitor is detected and connected. I go to the Advanced Display settings and also see that everything is in order. In short, software-vise my monitor is up and running while I see no picture. The cable has been tested to be OK, the monitor also. I get the same problem when I try to connect my laptop to my HDTV. Note that I use my VGA port to do so in both cases. I also have all the drivers updated.

If anyone can help me I'd be most grateful.

Some info: Laptop - Toshiba A210-133
Monitor: LG Flatron W2234S
OS: Windows Vista Home Premium 32bit

This conversation is currently closed to new comments.

Thread display: Collapse - | Expand +

All Answers

Collapse -

Cable issue

by robo_dev In reply to Odd external monitor prob ...

Is there ANY chance that the VGA cable you have is from another PC?

Believe it or not, there are different VGA pinouts within what we think of as a 'standard' VGA cable. Many devices use the more modern 'DPMS' (Display Power Management Signalling), which REQUIRES that both pin 5 and pin 9 are in the cable.

A 'classic' (my term) VGA cable will do everything EXCEPT proper power management. (This really messes you up with a KVM since the monitor won't wake up when it's supposed to).

The issue is that some cables are missing pin-5 and pin-9, pin-11 is the sense pin. Further, pins 5 and 11 are sometimes tied to pin-10 on some other cables, which effectively grounds-out the DPMS.

If you grab any old VGA cable, it would do the same thing with your TV, as TVs most surely use DPMS.

The 'old' standard was to simply drop horizontal-sync signal on pin 13 to invoke standby mode.

"Classic" VGA:
1 Red (Analog)
2 Green (Analog)
3 Blue (Analog)
4 Reserved
5 Ground
6 Red Return
7 Green Return
8 Blue Retuen
9 No Connect
10 Ground
11 (ID0) GND (Color)
12 (ID1) NC (Color)
13 Horzontal Sync
14 Vertical Sync
15 No Connect

Pin 1 RED Red video
Pin 2 GREEN Green video
Pin 3 BLUE Blue video
Pin 4 N/C Not connected
Pin 5 GND Ground (HSync)
Pin 6 RED_RTN Red return
Pin 7 GREEN_RTN Green return
Pin 8 BLUE_RTN Blue return
Pin 9 +5 V +5 V DC
Pin 10 GND Ground (VSync, DDC)
Pin 11 N/C Not connected
Pin 12 SDA I?C data
Pin 13 HSync Horizontal sync
Pin 14 VSync Vertical sync
Pin 15 SCL I?C clock

Collapse -

Reponse To Answer

by acaseltik In reply to Cable issue

That is an excellent suggestion. Thank you very much.

I've noticed that 2 pins are indeed missing from the cable I have here. This cable in particular I bought from a local shop when I simply asked for a VGA cable. I had no idea that it goes that deep. When I mentioned that I tested this cable (and it worked), I did it at a friend's house but on his desktop PC, so I can only guess that that made all the difference.

When I tested my monitor though I did it with my Xbox 360 VGA cable that has all the pins.

I will try to acquire a VGA cable that has all these pins you mentioned.

Thank you for your suggestion. I shall try this.

Collapse -

Reponse To Answer

by acaseltik In reply to Cable issue

I tried using the cable you suggested, but I just end up with the same thing, unfortunately.

Do you have any other suggestions? Could the VGA port itself be the issue?

Related Discussions

Related Forums