05/06/2007

How to check a setup for noise?

Dear Sales,
I have a new 10m HDMI cable. I connect one side to my VGA card through a DVI-HDMI adapter and the other end to a 32" LCD.
Its been working fine for months until now. Now all I get is a very green display, no red or blue components.
Cheers in advance,
Baz

Hi Barry,
It is possible that one of the components in your system is fault. Try a few of these tests below to see if you narrow it down.
1: Try un-plugging and re-plugging in the cable. When you do it inspect the pins in both the plug and the sockets to make sure they are all laying flat. If the plug has been forced sometimes a pin can fold back - so inspect carefully. If the pins are OK (both ends of course) reconnecting will eliminate ‘dirty contacts’ problem as any small bits of dirt or oxidization will be removed. Check the pins in the adapter too - the DVI side of which is unlikely to be affected however as DVI is a tough-old military spec connection.
2: Swap the cable around, plugging the DVI-HDMI adapter on the other end. HDMI is symmetrical and bi-directional, so effectively this should not change the picture. In the unlikely event it does is could be a faulty cable.
3: Plug something analogue into the Hitachi. Plug in a VCR or DVD using SCART just to check the colour processing on the Hitachi is working fine. If its not - the LCD is going to be at fault.
4: Swap out the HDMI cable for another one. This may not be possible/practicable of course and another idea might be to take your cable to a local TV retailer and ask him to hook it up to a DVD and TV to check it out.
5: Hook up the VGA card to a PC monitor with DVI input. This should let you know if the output of the VGA card is at fault or not.
Best regards,
Richard

Dear Richard,
All other inputs into the LCD work but I found that the DVI2HDMI adapter, the TMDS 1+ was shorted to the shield (GND).
So I might as well buy another adapter!
Regards,
Barry

01/11/2010

Webmaster's comment on HDMI 1.4:

All current TECHLINK HDMI cables up to and including 3 meters in length are HDMI 1.4 certified by HDMI Licensing, LLC.

Currently the HDMI organization only tests and certifies HDMI 1.4 cables up to and including 3m in length. There is no test for longer lengths which means any manufacturer claiming official HDMI specification of any variety for cables over 3m is making an erroneous statement. On the other hand - TECHLINK have undertaken technical and specific "real-world" tests of our long HDMI cables with a variety of HDMI enabled devices and have found all our cables attain or surpass the HDMI 1.4 specification.

The main concern for consumers is whether a cable or adaptor supports the HDMI 1.4 specification. We have tested Wires cables up to 15m (and up to 50m when used with the Wires Repeater) with a 1080i/p and with 4K sources and got a perfect picture. However, the quality is ultimately dependent on the source equipment - we have designed our cables to handle 1080i/p and 4K x 2K resolutions and 99.9% of all the source equipment we have tested so far has worked faultlessly.

All HDMI crossover cables and adaptors, such as HDMI to DVI cables, are HDMI 1.3 compatible due to limitations in the DVI specification.