Why are the colours all wrong?
This is a reasonably common fault that you will come across from time to time. The customer will call & say “I’m trying to project my laptop and all of the colours are wrong or wierd”. The most common cause of this is a simple cable fault. When using a composite video output, the red green and blue signals are sent seperately. If one or more of the pins on your VGA cable become bent or broken, your picture will lose a colour or two.
First, make sure that the cable is actually plugged in properly and isn’t half hanging out. If the cable is in properly, carefully unplug it and inspect the pins for bent or broken ones. Most times it is very hard to bend a pin back into position once it’s been damaged and it will usually break when you try. The only fix for this problem is to replace the cable completely. Once again, have a backup!
Tips for an effective presentation - backup your media
I saw something funny once. At least it was funny to me! To the person involved it was a tragedy.
A person arrives at a venue in order to give a very important presentation to a live audience. They arrived just before they were due to speak and shoved a battered and scratched CD into the computer. This is when the fun started. The computer refused to read the CD at all. At this point the person presenting started to become quite agitated and started blaming the audio-visual equipment which happened to be in pristine condition. The A/V operator, being a professional, calmed the presenter a bit and convinced the person that maybe their scratched and dented CD might be the cause of the problem. The presenter then asks the obvious question; “What do I do now?” to which the A/V person replies; “No problem, just use your backup.” “Backup?” was the reply. “Surely you have a backup?”
Well, as it turned out the person did not have a backup and then had to deliver a long lecture with no visual aids at all, and do the whole thing by memory.
It sounds basic and it sounds like common sense but most people don’t do it. Have a backup folks!
- Have more than one CD and make sure you’ve tested them all thoroughly. If they are scratched, then replace them.
- Take a USB memory stick with you as well. Pick one that does not need to install any drivers to run. That is most of them these days but check it.
- If you can, burn a DVD as well… just in case.
- Leave a master copy at home or in your office. A lost or stolen laptop bag with all of your backups in it is useless.
I may seem a bit over-cautious but it’s like the old adage about “take an umbrella and it never rains.” Play safe and have backups folks.
How does a Public Address system work? Part 1 – Overview
A Public Address(PA) or Sound reinforcement(SR) system is a collection of equipment that is used to amplify(make louder) or distribute music or speech to an audience. It usually has the following components:
- One or more microphones. A microphone converts sound waves into an electrical current. The electrical signal can then be processed in a variety of ways such as mixing it with other microphone signals.
- A power supply. This could be anything from a battery to a generator but is more commonly just a mains power supply.
- One or more amplifiers. An amplifier takes the basic electrical signal from our microphone or other sources, and multiplies(amplifies) it greatly. The electrical signal then has the necessary current to move a speaker.
- One or more speakers. The speaker converts the amplified electrical signal back into sound waves by vibrating back and forth.
Consider the PA system in it’s simplest form, the megaphone.
The megaphone has a microphone at the very back which you speak into. It has batteries for a power supply. It has a small amplifier which feeds into a speaker at the front. The whole system is built into the one unit.
All PA systems, from the humble megaphone to the largest concert or stadium system, follow that basic format. In our next look at PA systems I will explain a bit more about the first step in the chain, the microphone.
Should I switch the laptop or the projector on first?
In most cases you should connect your laptop to the projector & switch on the projector first. This way the laptop will see the projector when it boots and some will even connect automatically.
Using a laptop with a projector or monitor
In order to use most laptop or notebook computers with a projector or external monitor, you will usually have to enable the port. This usually involves a “Function” or “F” key combination. Some of the more common key combinations are listed below.
Hold down the Function key, normally located in the bottom left-hand side of your keyboard, and then the appropriate F key across the top of your keyboard.
Most laptops will cycle or toggle through a series of modes when using the F keys. The push might give you the Laptop screen only, push it again to enable the external port, push it again to enable both screens. Some will even disable all screens. If you don’t get what you want immediately then just hit the F key again to cycle through your options.
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Welcome to AVHints
Welcome to AVHints.com
In this site you will finds all kinds of helpful hints and tips for those who use or work with Audio-Visual equipment or systems. Some of the articles will be aimed at the novice end-user and some will be quite detailed and aimed more at the A/V professional. Please call in often & don’t be frightened to ask questions, make suggestions or to offer comments. I’d love to hear them.
Cheers, Mark Gibson