How do I access the filters on a Dell1201MP Projector to clean them

filter is on the top right hand side of the projector. you will have to remove 2 screws and lift the handle to the filter cartridge to access it.

you need to clean dust filter and replace filter if required
it depends on which model u are referring to
this message is seen generally in the hi end models only - DLP range in access of 4000 lumens

Air-Filter
Cleaning the Air Filter
The air filter should be cleaned as described below at intervals of approximately 100 hours. When
the filter is used for approximately 100 hours, the message "CLEAN THE AIR FILTER" appears
when the projector is switched on.
1 Switch the projector power supply OFF, and remove the power cord from the power outlet.
2 Clean the air filter with a vacuum cleaner.
3 Reset the Filter Timer using the function of the FILTER TIME on the OPTION Menu. Please
refer to the description of the "FILTER TIME" on the Table 9: MAIN Menu.
Replacing the Air Filter
Replace the air filter if contamination cannot be removed, or if it is damaged. To order a new air
filter see page 26 for contact information.
1 Switch the projector power OFF, and remove the power cord from the power outlet.
2 Remove the filter cover and the filter.
3 Replace the new air-filter and the filter cover.
4 Reset the Filter Timer using the function of the FILTER TIME on the OPTION Menu. Refer to
the description of the "FILTER TIME" on Table 9: MAIN Menu.

There are four air filters that are accessible from the bottom of the projector .... make sure they are all clean.

This particular projector does not have filters. As per their website, "The filter free design of this projector, along with the long life lamp (up to 4000 hours operating time, mean less ongoing maintenance on the projector." from https://www.mitsubishielectric.com.au/1630.htm.

Cleaning instructions from the manual are: "Cleaning of the projector and the ventilation slots

Use a soft cloth to clean the projector and the ventilation grilles. When the grilles become dirty, wipe them with a soft cloth dampened
with diluted mild detergent, and then wipe them with a dry cloth."

As long as you have access to the panel covering the filter, you can clean it quite easily using canned air or if you happen to have a household compressor, you may use that as well. Just take care not to use to high of pressure when blowing out the dirt. This may cause a tear in the filter.

WARNING ?Before caring, make sure the power switch is off and the
power cable is not plugged in, then allow the projector to cool sufficiently. The
care in a high temperature state of the projector could cause a burn and/or
malfunction to the projector.
?Use only the air filter of the specified type. Do not use the projector with the
air filter and filter cover removed.
?Avoid wetting the projector or inserting liquids in the projector. It could result
in a fire, an electric shock, and and/or malfunction to the projector.
CAUTION ?Please replace the air filter when it is damaged or too soiled,
and also when you replace the lamp.When the indicators or a message prompts you to clean the air filter, clean the air filter as soon as possible. If the air filter becomes clogged by dust or the like, internal temperatures rise and the power may be automatically turned off for malfunction prevention.
1. Turn the projector off, and unplug the power cord. Allow the projector to cool for at least 45 minutes and prepare a vacuum cleaner.
2. After making sure that the projector is cool adequately, slowly turn the projector so that the lens-side is facing up. Please be careful for a projector not to fall. While the projector is placed lens-side up, hold the projector.
3. Putting a finger on the filter cover's knob, slide the filter cover in the direction of the arrow to remove it.
4. Holding the air filter's knob, pull the air filter off.
5. Apply a vacuum cleaner to the vent of the projector for the air filter. And then slowly turn the projector bottom up.
6. Apply a vacuum cleaner to the air filter and filter cover.
Please replace the air filter when it is damaged or too soiled.
To prepare a new air filter, contact your dealer and tell the air filter type number = NJ09702.
An air filter of specified type will come even with the replacement lamp for this projector.
7. Position the cleaned air filter or a new air filter into place, and push the points
of "PUSH" word with claws to fix the air filter.
8. Replace the filter cover and snap it back into place.
9. Slowly turn the projector so that the top is facing up.
10. Turn the projector on, and reset the filter time using the FILTER TIME
function of OPTION menu (?37).
NOTE • Incorrectly resetting of the filter timer (resetting without replacement,
or neglect of resetting after replacement) will result in incorrect message
functions.

First, to rule out true overheating, clean any dust filters and air-access areas. There might be enough dust on the filter to cause a gradual build-up of heat which could trip one of the temperature sensors in the unit. I clean my projector once a week--There might be a cooling fan going bad--after a while, heat causes the fan motor to start to drag and slows down the air flow. Also, there might be a temp sensor that is shutting down the unit prematurely.--Rick

On the right side of the projector there are vents, put a vacume cleaner up to the vents, and the filter will be cleaned.
then on the top of the projector click the down arrow, then go down to option, use the down arrow to highlight the filter time, then hold the reset button on top of the projector for about three seconds. Clean the air filter every 100 hours.

Hi Here is the info for you :: Caring For The Air Filter The air filter should be cleaned about every 100 hours. If the indicators or a message prompts you to clean the air filter, clean the air filter as soon as possible. If the soiling will not come off the air filter, or it becomes damaged, then it needs to be replaced. Please replace the air filter as soon as possible. memoWhen you replace the lamp, please replace also the air filter. Turn off the projector, and unplug the power cord. Allow the lamp bulb to cool for at least 45 minutes. Apply a vacuum cleaner to the top of the filter cover and the air filter to clean. If the soiling will not come off the air filter, or it becomes damaged, it needs to be replaced. If the air filter needs to be replaced, contact your dealer to prepare a new air filter. Tell the dealer your air filter type. Turn on the projector power, and reset the filter timer. (1) While the projector running, press the MENU button to open the menu. (2) Choose the ?OPTION? on the menu using the / button, then press the button or ENTER button. (3) Choose the ?FILTER TIME? using the / button, then press and hold theRESET button for 3 seconds. (4) Choose the ?RESET? using the button. memo Incorrectly resetting of the filter timer (resetting without replacement, or neglect of resetting after replacement) will result in incorrect message functions. Here is the link to the users manual :: http://www.aboutprojectors.com/Hitachi-CP-X1250-projector.html Further Questions ?? Email Me [email protected] Have a great evening.