Sanyo pro-x projector problem

[andythomas]

Hi there,

 

I have a Sanyo Pro-X projector which has a problem. When projecting onto a wall/screen from a laptop, there seems to be a lot of shadowing going on, and no red colour shows - it shows as black.

 

Any ideas as to what is going on? Is it a bulb inside the machine gone (perhaps the red one - if this is how it works)??

 

Please help!!

 

Thanks

[danielbrown]

Shadowing could be sync problems both problems can be caused try a short cable (VGA I assume) direct into the projector could save a lot of head scratching

[Dave]

Sanyo use the term "Pro-X" for many projectors - it would help if you stated the exact model number. Whilst some Sanyo projectors have multiple lamps, they are very large and expensive and I can't imagine that yours does.

 

The chances are, as Daniel said, it is a duff cable (VGA cables are not known for their reliability). You could also try feeding it with composite video from (eg) a DVD player.

[soundo26]

Firstly you should check your lead, the red green & blue signals travel separately along the lead as do the horizontal & vertical syncs, your problem could be that there has been a disconnection within the lead, also check the 15pin plugs, it is common that a pin gets bent or broken due to rough handling, please note that there is often 1 pin missing by default.

Another problem can be due to a mismatch between what you are sending and what your input is expecting, signals come in many flavour such as RGB, RGBS, RGBHV, RGsB, the difference is the way the sync signals are taken in, some projectors and scalers etc have inputs where this can be configured, the most common for a 15pin D sub plug (or 5xBNC plugs) will be RGBHV, if the signal is coming from an older device such as an analogue interface it may use four BNC connectors in an RGBS configuration, only 3 will be RGB or could be RGsB (where the sync is combined with the Green signal. Experimentation with these settings may be required to find out!

 

Having said all that, one of the likely causes would be that you may be running the signal too far unamplified or through sub quality cable. The signal that comes from the 15 pin output at the rear of your PC or laptop was only ever designed to run to your moitor through a lead of a maximum 3 metre lead, if you are running longer distances you should be using good quality cable & connectors, with no joins (there can be a 5db signal loss for each connection used) an amplifier such as an Extron P2DA2, 4 or 6 should be used at the PC end, this will amplify the signal enough to send the signal up to about 250ft (but not from the local monitor output which is unamplified). If you buy a cheaper type of amp, be sure to check that the bandwidth is 300Mhz or greater, older or cheaper equipment may be as low as 100Mhz. The bandwidth factor is one that will affect your image quality most. The system (the rig from source to end) bandwidth's integrity is only as good as it's lowest Quality component, you can have top class equipment all through the system, but can destroy the end signal by using 1 item of equipment or cheap cable, the bandwidth of the whole system will drop to the level of that piece and result in things like tearing of vertical ascenders in text & Ghosting.

 

Ghosting can also occur if you try to split the signal in an unconventional way (a buffered splitter should always be used) or if the endpoint isn't terminated, the ghosting is a reflected secondary signal(like an echo) caused by the singnal reflecting back towards the source. Most modern equipment automatically terminates but problems can occur if the termination cicuitry degenerates but if you are using a splitter or amp which has a switch marked "term" or 75 ohm this should be set to off, termination switces should only be used at the end of a signal chain.

 

Hope this helps, if you need more info check out the Extron website which I believe has loads of training articles on it. I believe RGB Communications near Newbury do data training, you'll have to google for the addresses.