Audio Visual Technician Dun Laoghaire

joeguevara

I have just installed a projector in my house in dun laoghaire. This is connected to UPC and a surround sound system. However, there is interference with the projector and after doing research, I believe it comes from a ground loop and video hum.

I was wondering if anybody could recommend a good AV technician in the dun laoghaire area who would be able to fix this. I am completely technically challenged.

Cheers.

ZENER

Can you describe the effect you see on screen ? What length and type of cables have you used to connect the video signals ? I'm guessing it's analogue ?

Ken

joeguevara

ZENER wrote: »

Can you describe the effect you see on screen ? What length and type of cables have you used to connect the video signals ? I'm guessing it's analogue ?

Ken

There are two effects. One faint white bars going up and down the picture. Second interfwrence. Best way to describe it is when the tracking on a video. That is intermittent. Lets say wvery 5 minutes for 3 seconds.

I dont know what cable. Could be analogue. However, the above happens if connected into upc box or straight into dvd player. I did some research and it may need a ground breaker. But again I could be totally on the wrong track.

ZENER

Is the connection HDMI - SCART or Composite Video ? Sounds like a bad cable or a cable insufficiently shielded. Almost definitely analogue because the artefacts you describe could only occur on an analogue type signal.

Approximately how long is the cable between the source and the projector ?

What's the make/model of the projector ?

Is the connection directly from the UPC box to the projector or does the video signal go through another device like a home cinema amplifier ?

Any/all info you provide will help with a diagnosis.

Ken

joeguevara

Name of projector is a benq.

Projector to source is 12 feet.

Connection is through home cinema amplifier.

Thanks for your help on this.

ZENER

Unless you can provide some information there's little any one can do to help you.

It sounds like you're using an analogue type signal but which one ? What does it say on the connector ? When you bought the 12 foot cable what did you order and pay for ? Maybe a photo of the cables connected to the projector would help ?

The interference happening every few minutes is odd but does point to either a poor quality poorly screened cable or an incorrectly fitted one. Is it possible to connect a scource directly to the projector via the 12ft cable but without going through the home cinema amp ? Do things improve ? Disconnect the cable from the UPC box, does that make a difference ?

Ken

joeguevara

ZENER wrote: »

Unless you can provide some information there's little any one can do to help you.

It sounds like you're using an analogue type signal but which one ? What does it say on the connector ? When you bought the 12 foot cable what did you order and pay for ? Maybe a photo of the cables connected to the projector would help ?

The interference happening every few minutes is odd but does point to either a poor quality poorly screened cable or an incorrectly fitted one. Is it possible to connect a scource directly to the projector via the 12ft cable but without going through the home cinema amp ? Do things improve ? Disconnect the cable from the UPC box, does that make a difference ?

Ken

Just to update. Nothing to do with cable. Btw the cable was composite vide (whatever that means). It wasn't HDMI. The problem was with the earhting rod in the house. It wasn't the correct size. Not dangerous. This was creating electrical interference. Removed grounding earth in the projector as a short term fix. Sorted.

ZENER

I can only imagine the awful picture quality ! A Standard Definition composite video picture delivered via 12 feet of poor quality cable projected onto an 80"+ screen. Replacing that cable with HDMI cable will make a world of difference and eliminate the interference all in one go.

Difficult to understand how a small earth rod could lead to the interference you're experiencing ?!

Ken

joeguevara

ZENER wrote: »

I can only imagine the awful picture quality ! A Standard Definition composite video picture delivered via 12 feet of poor quality cable projected onto an 80"+ screen. Replacing that cable with HDMI cable will make a world of difference and eliminate the interference all in one go.

Difficult to understand how a small earth rod could lead to the interference you're experiencing ?!

Ken

The picture is fantastic. I've had projectors with hdmi in my other house, absolutely no difference. The expert who was out got it right. So imagine away the awful pic.

The original op asked did anybody know an av technician. Your response regarding the cable was completely wrong. If I had changed the cable the interference with hdmi would have been worse. Glad I waited on an experts advice. Hdmi cables do not get rid of ground loop.

ZENER

No difference between HDMI and composite video ? . . . enjoy your new projector ! Please tell us the name of the expert.

Ken

joeguevara

ZENER wrote: »

No difference between HDMI and composite video ? . . . enjoy your new projector ! Please tell us the name of the expert.

Ken

There is obviously a difference. But I would have to do a shed load of work to get the interference. I'm happy with my picture. I'm happy it's sorted. As I said if I had replaced the cable it would not have fixed the problem.

You couldn't answer the problem and you gave the wrong advice. And now your acting like an arrogant pr1ck. But as long as people don't overtake you wrongly. That's all that matters.

ZENER

Seriously ?! What has driving got to do with earth loops and video quality ? Firstly - HDMI uses differential signals, that means they are immune to common mode noise like earth loops would generate.

Also an earth rod is only required as a return path to earth where no other exists, i.e. in an emergency. All normal current wants to return to its source. The positive in your car wants to return to the Negative etc.

Your interference is most likely due to an appliance with a poor connection to Neutral, get your fuse board checked is my advice as an electrician, get a different "AV Expert" is my advice as an AV Technician and provide more information in future if you want a useful answer is my advice as someone who was simply trying to help you.

Ken

rednik

Bad form to someone trying to be helpful.

Twistedlace

I totally agree with ken. I have been working in the business for 15 years doing houses/ hotels/shops/bars/nite clubs /and I have seen every manor of faults on TVs/projectors/led screens/plasmas/and I know this to be right hdmi will give you a clear picture all day everyday and if for some reason there is a fault on the cable run you just won't get any hdmi picture. And for the story about composite being the same as hdmi.Go to the back of the class and slap yourself with a rotten corn beef sandwich.and don't be listening to part time house destroyers here end it the lesion