Take apart I want to gain access to the fans so that I can blow out 4 years worth of dust.

The most common cause is dust inside the projector that leads to overheating & auto shutdown. If you have an air compressor you can use the blow tip accessory to blow as much dust out as you can without taking apart the projector. You may get by using a can of compressed air available at Walmart, etc. electronics section. Concentrate on vented areas & where you can see or hear any fans. Do this outside so it doesn't make a mess. If you know how to take out the lamp there's usually close access to the main cooling fan through the lamp compartment, blow air through there & it will follow the right path to exit correctly without blowing dust all over the inside.

I just blow compressed air through the laptop from all of the vents. I do this every few months and haven't had any problem. Taking a laptop apart isn'y easy, there are lots of different sized screws, and often non-standard screwheads which most people do not have the screw driver to remove them.

Start as far away from the fan output as possible and work your way towards it. It is best to use air from a compressor and NOT a spray can as you need lots of air flow, and lots of air in general. Using a can is fine for blowing a laptop every month or so.

Have you tried blowing air through the cooling duct to clean out the dust that gets caught up in there?

The cooling fan needs to be replaced or there is to much dust and dirt buildup blocking the intake of the heatsink. The laptop must be taken apart to access the fan and heatsink, remove them both and use a can of compressed air to blow any dust buildup, next! remove the old thermal paste from the processor and heatsink with rubbing alcohol and a paper towel, replace with new and assemble, this will solve most thermal problems.

Three things that will make a laptop overheat:

1. Dust - Dust inside the laptop, dust clogging the vents, dust around the fans, dust around the cpu and heatsink. To fix it, take the laptop apart, take a can of compressed air and blow out the dust.

2. A fan is not working. To fix it, you will have to take the laptop apart to replace the fan.

3. The Thermal Paste around the cpu and heatsink has dried up or is too thin to keep the unit cool. To fix, take the laptop apart and apply a fresh coat of Thermal Paste.

Another work around for a laptop that is overheating is to by a Laptop Cooling Pad that has fans on it and it plugs into the usb port of the laptop. The laptop sits on it and it keep the laptop cool. You can buy a laptop cooling pad for less than $20 from Tiger Direct.

http://www.tigerdirect.com

When the site opens just type Laptop Cooling Pad in the search box at the top of the screen then press GO. Sort the returned results by Price Low to High.

Almost certainly a clogged cooling fan , vents or build up of dust on the cooling fins. You will need to gain access to the CPU fan and remove the heatsink assembly, blow all dust out of the cooler matrix, clean the fan blades and the cooling vents. Clean off any thermal paste on the cpu and regrease with new paste, refit and reasemble.

You CAN cut corners by cleaning it "in situ" but a thorough cleaning is advised.

Eventually if not cleaned, teh graphics chip will fail with overheating

There are 6 screws, deeply recessed, in the rear of the fan case. (At least that is how they are on mine, phillips or cross head)
Once they are loosened, the front and back will come apart. I Do that annually so it can be thoroughly cleaned..
Otherwise, I use a toothbrush to fit between the slots to get most of the dust, also a paintbursh with stiff bristles for the outside grills.. Similar small brushes should work for loose dust. Also can blow out loose dust with a shop vac with blower capability.

A common problem with all laptop is dust. Sounds like you have 5 years worth of dust stuck in there. You should get a can of compressed air and blow though every vent you can! You want to loosen the dust that's in there and possibly try to blow it out and/or get it closest to the vents.

After that you should take a vaacum cleaner and **** out all the dust you can!

Dust inhibits air flow, alot! Its the number 1 killer of old computers.

the issue is likely thermal shutdown (it got to hot) listen to establish whether the fan(s) are working. you will need to take it apart to gain access to the fan area to clean out the dust and dirt.

this can be one of two things, if the fan blades are chipped in anyway then the fan will be out of balance and wreck the bush that the fan runs in, i would say that its more likely to be dust thats worked its way into the bush and its running dry...my advise is to buy a replacement fan that are not expensive, give the unit a good blow out before you fit a new one
a "get you out of trouble" remedy would be to gain access to the fan spindle and put a drip(and i mean a very small drip) of light oil to lubricate the fan..ive done this on pc fans for years but its better to replace them in the long run.