Need advice about projection problem

[Richard Akins]

SYSTEM: The video output from our XP PC goes to a Altinex DAFPI100 1-in, 4-out VGA distribution amplifier. One of the “local” outs goes to a monitor on the control desk. One of the “equalized” outs goes 75 feet to a Smart View VS-814PF 1in, 4 out video splitter (6 years old) and then to 3 choir monitors. The other “equalized” out goes 100 feet to a Panasonic PT-D3500U DLP projector (3 years old with a 3 month old bulb) hanging from the ceiling.
PROBLEM: In the last month the image from the projector has, now and then, shown a horizontal jagged bar which finally “pulls” the image off the side of the screen. The screen remains black for 2 or 3 seconds and the picture returns, only to repeat the loss of image in 10 to 20 seconds. It looks a little like the horizontal hold TV problems of old. None of the other monitors show this fault. I have reversed the connections to the two “equalized” outs, but the results are the same. I ran tests for 5 or 6 hours during the week without any failure, only to have the problem show up again on Sunday morning.
WHAT TO DO? My (very amateurish) view is that the video amp is failing to produce a strong enough signal at the “equalized” outs or there is a malfunction or bad connection at the projector. I would like some advice as how to proceed in that a new video amp will cost a few hundred dollars and doing anything to the projector requires scaffolding and 4 men’s time for about 4-5 hours. I’m in a small town and I’m not sure how much reliable outside expertise I can find.
Thanks for help. Dick

[tdangelo]

Richard,

Are you able to bypass the existing cables, splitters and DAs and feed the projector from the computer with a short cable as a test?

[Richard Akins]

No, the projector is suspended from the ceiling and is 20 feet from the floor -- scaffolding has to be used to get to it. I'm trying to get the most likely source of the problem so that I can, perhaps, minimize the wasted labor and money. Thanks for your reply.

[tdangelo]

Richard,

If testing the components through a process of elimination cannot be done I would try the following:

1) having two amplifiers upstream of the projector is not ideal. It is possible that you are amplifying noise/hum/etc., in addition to amplifying the VGA signal. Can you eliminate the first amplifier as a test and temporarily connet the PC right into the second amplifier?

2) Has anything changed recently which could potentially cause damage to the cable going to the projector?

3) If the projector is being fed by the same DA as the other screens, can you move the projector to another spigot on the second DA?

[shane2943]

+1 to the above advice.

Also, I'd like to add that new video VGA amps are not hundreds of dollars. They're about 30-50 dollars for decent equipment.

[Richard Akins]

Thanks for the suggestions, Tom & Shane.
1) There is only one amp on the projector line -- the two are on the choir monitors.
2) To my knowledge, nothing has changed recently.
3) The projector, choir monitors, and desktop monitor are all on the same distribution amplifier -- I reversed the projector & choir monitors, but the projector still flickered.

I'm not sure what the difference is, other than price, between distribution amplifiers (a few hundred $$) and powered splitters (30-50 $$). The easiest thing may be to buy a powered splitter and see if the problem goes away. If not, then I guess will have to get scaffolding and try to find out what is wrong with the projector.

[tdangelo]

Richard,

OK, I think I understand your set-up now. Does this drawing describe it?

[Richard Akins]

Yes, that is the arrangement. The choir monitors and projector are on "equalized" outputs and the control desk monitor on a "local" output.

[shane2943]

Not sure what "equalized" means on that DA.

IOGear makes a real decent VGA splitter/amp. We use two of them to push the primary and foldback VGA signals over 4 100VGA cables (2 to the front projectors and 2 to the rear (foldback) projectors). Not even so much as a hickup with them. The specs on them say they can push a VGA signal over 200ft. They were around 35 dollars IIRC. I'll dig up a link...

If anything, it'd be cheap troubleshooting to swap in a splitter/amp and see if your problem goes away.

[shane2943]

Yeah, here we go, this is the one we use:

http://www.newegg.com/Product/Produc...-066-_-Product

[[Admin] osborn4]

Originally Posted by shane2943

Yeah, here we go, this is the one we use:

http://www.newegg.com/Product/Produc...-066-_-Product

Interesting that they show a pic of almost every side except the back, which is where all the plugs are.

[shane2943]

Now why would you need to see that side? Aint like there's anything important on it.

I can describe what's there:

4 VGA Female ports (output)
1 VGA Male port (input)
Small round port for power supply brick

That's it. No buttons or anything. Can probably google its model # for port pics. Posting from my phone so that would be cumbersome else I'd just post a pic.