Dual Monitor (HDTV) Problem Radeon HD3450

lafargeotte · 28 Jul 2010

I'm using a Radeon HD 3450 on Windows 7 with Catalyst 10.7

My monitor is connected through the VGA port, and it works fine.

I tried to connect my HDTV (LG 50PK350) as a second monitor through the HDMI port (on TV & HD3450). The TV (as 2nd monitor) is not detected and there is no signal on my TV.

The connection appears fine, as when I click 'Detect Displays' in CCC, the pc monitor screen flickers and tries to connect but eventually fails. (same using Windows 7 Display properties!).

I am using a brand new HDMI 1.4 cable.

Any ideas?

TIA

stormy13 · 28 Jul 2010

Card have VGA, DVI and HDMI ports? If so the reason it won't work with the HDMI and VGA at the same time is both of those ports are running through the same RAMDAC, and only one of them can be used at a time.

If you can hook your monitor up to the DVI port using either a DVI cable, or if the monitor doesn't have a DVI port on it the card should have come with a DVI-VGA adapter. If it didn't you should be able to find one fairly cheaply, like this one,

Newegg.com - SAPPHIRE DVI to VGA adapter for Twin-View video cards Model DVI-2-VGA - Video Card Accessories

lafargeotte · 28 Jul 2010

OK Thanks.

Explains why it works OK on TV without the VGA monitor being connected!

Zepher · 28 Jul 2010

Doesn't the HDMI and DVI use TDMS?

from wikipedia,

As the use of DVI, HDMI, and other digital interface technology becomes increasingly mainstream, the
"DAC" portion of the RAMDAC will likely become obsolete. Digital interfaces use a TMDS module.

Mellon Head · 28 Jul 2010

That's a pretty weak card. I used to have one and gave it up. I never got the HDMI port to work by itself, much less with another monitor connected. If you need to have HDMI and another connection, you might want to upgrade to a slightly better card.

lafargeotte · 02 Aug 2010

Hi Guys,

Thanks to stormy13's advice (the RAMDEC) I have solved the problem.

Now have HDMI & DVI connections (done away with the VGA).

Mellon Head the card satisfies my needs (not a gamer of any sort).

Thanks again this forum for another problem solved.

Mellon Head · 02 Aug 2010

lafargeotte said:

Mellon Head the card satisfies my needs (not a gamer of any sort).

Thanks again this forum for another problem solved.

Glad you got it fixed. It's kind of nice to see someone happy with their hardware and not always going for bigger -> better -> more. I'm that way too. My video cards are a little old, but they do everything I need them to.