PC image refusing to display on LCD screen

Reeves · Fri 20 Nov, 2009 23.23

Another issue has arose. I've connected my old PC up to run on my LCD TV as a media center. Everything works fine, the startup screen is fine and I can clearly see the Windows XP logo. However, when any BIOS details attempt to come up, or Windows itself starts, I see nothing on the screen. Instead, the screen flickers on and off fast enough so nothing is actually visible on the screen.

I can't see how this is a problem with the VGA lead as the Windows XP loading screen comes up fine. I've tried entering Safe More or something to alter the screen resolution if that was the case, but nothing but flickering seems to occur. What's causing this?

Many thanks in advance

Beep · Fri 20 Nov, 2009 23.36

Reeves wrote:What's causing this?

Screen refresh rate?
Try connecting on a normal monitor and seeing what setting it's on. If you can, change it then reconnect it to the tv, see if you get a difference.

cdd · Fri 20 Nov, 2009 23.46

LCDs don't have refresh rates so that's definitely wrong...

Sput · Fri 20 Nov, 2009 23.52

You're wrong, cdd. They need to be driven at some horizontal and vertical frequency, at least using analogue connectors, and the electronics limit that. I doubt it's an issue here, because windows will usually revert to a safe VGA configuration if it sees an unrecognised screen connected.

cdd · Sat 21 Nov, 2009 00.08

I'll defer to your judgment although I'm not sure I understand... my idea was that since LCDs work by changing colours of pixels on the surface then the image doesn't have to be re-flashed every x seconds as with CRTs.

But perhaps I'm confusing two different concepts!

dosxuk · Sat 21 Nov, 2009 00.56

LCD monitors in my experience are more picky about refresh rate than CRTs. CRTs basically just slaved the tube to the incoming signal, meaning an unsuitable refresh rate would result in some sort of picture, but one either unusable due to flicker or not lined up on screen properly. LCD monitors buffer the incoming signal and use that to drive the LCD panel, but they have a set range of frequencies that they can actually read data from, and if you send a refresh rate outside it's range, it won't display anything (apart from an "Input signal out of range" message if you're lucky).

Reeves · Sat 21 Nov, 2009 01.13

If it's any help in terms of getting to the problem, the original monitor the PC was used with was LCD. The issue with this is that it's a Toshiba LCD Television I'm trying to connect it to.

Dr Lobster* · Sat 21 Nov, 2009 09.28

is it possible to try the following:

1) change the video cable
2) plug another device into the tv, such as a laptop to see if it's an issue with the graphics card or tv (preferably with a known working cable)

at least if we can identify where the problem is, we can work out hopefully how to fix it.

Andrew Wood · Sat 21 Nov, 2009 15.03

Quick question - have you tried booting to Safe Mode (pressing F8 during the boot sequence)?

If you get the display to work, you may need to check your video and monitor drivers' settings.

Beep · Sat 21 Nov, 2009 16.34

Andrew Wood wrote:Quick question - have you tried booting to Safe Mode (pressing F8 during the boot sequence)?

Reeves wrote:I've tried entering Safe More or something to alter the screen resolution if that was the case, but nothing but flickering seems to occur.

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It could just be a faulty VGA in on the TV

Andrew Wood · Sun 22 Nov, 2009 01.35

Bugger - must remember to read every word of a post and not just scan through. I might end up looking stupid otherwise...!