Whats it mean when the projector says to check the airflow every few hours on the screen. The projector is a Hitachi CPX440

Here is a link to a forun that explains whats happening.
http://www.avsforum.com/t/1441789/black-and-white-dots-all-over-my-projector-screen-what-causes-it

sorry but the serial number doesn't tell anything about a set, the model is what you need first, it could be lamp but don't know the model

reset the filter hours if you are able and re-flash the firmware

Many Hitachi projectors use 3LCD technology which supposedly makes colors more realistic. 3LCD means that the projected light must pass through 3 seperate LCD screens. Each screen has one color but when mixed, they form a nice picture. I would guess that one or more of the LCD screens have gone bad. That is a hardware problem that I would recommend talking to the manufacturer about.

This means you may have an obstruction preventing airflow from circulating properly. If this is the case, it can lead to overheating of the projector, which could result in very expensive repairs.

You need to regularly clean the air filter and rest the filter timer to ensure that your projector can cool itself properly. I recommend doing this every 100 hours of use. In fact, Hitachi projectors can be set to warn you when a certain amount of time has elapsed. I believe 100 hours is the default.

If cleaning the air filter and resetting the filter timer does not remedy this, you can use canned air to blow out the inside of the projector and try to clear the obstruction.

You also want to make sure all fans on your projector are working. If not, stop using the projector and replace those as soon as possible.

Overheating is the leading cause of projector malfunction, and basic routine maintenace can increase the life of your projector and the lamp by a great deal. For example, the lamps for that machine are typically estimated to have a life of no greater than 2000 hours, and typically you'll see them go out anywhere from 1300 hours to 1600 hours. Because I regularly check my machines, the ones that are not used intensively for hours on end every day will often have a lamp life of over 2000 hours, and I found one recently that made it to 3100 hours.

Most likely you have a defective lamp or it is near the end of its life. It's also possible that the high voltage power supply is going out. You might check the lamp hours - you can find this in the advanced menu. Also check the air filter, if you haven't cleaned it, the airflow might be restricted, shutting down the projector.

Usually this means convergence ic's have to be replaced and possibly a few resistors on small convergence board. Sometimes it requires digital alignment after new parts are soldered in. This repair can cost 175.00-375.00.

i believe you hit the up and down arrow and the enter button on the projector itself and hold hem in for few seconds and it will display lamp usage.

The fan may have went bad. If it's out of warranty you may open it up and try and blow some dust out of the fan to see it that may do the trick if not it may need to be replaced. Westexaudioelectronics.com

You need to clean the filters. When the filters collect alot of dust on them, they block the airflow to the internal parts of the projector and can cause the bulb to blow due to the temperature getting to hot.