Color bleed and Fan

My unit never got to the point of actually shutting down due to overheating, but your problem may be related to what I experienced: A bent lamp heat shield.

My Optoma EP739 started exhibiting color-banding and strong color shift after years of great service. After trying other suggestions that didn't work, here is the FIX for my unit. I have not seen this posted anywhere else.

Problem: After 10-20 minutes of use, color-banding and then a strong shift to purple/green with almost no red. If the unit is turned off for 5-10 minutes to cool and then powered-up again the problem goes away, only to come back in another 10-20 minutes. Enabling the "High Altitude" setting in the Setup Menu helped for a while (a week or two) since it forces the main cooling fan run at high speed always, but then the problem re-appeared.

Reason: Overheating. The electronics are overheating. Like several people have suggested: First step: Open the unit up and blow-out/vacuum all of the accumulated dust. Assure BOTH fans (there is a small drum blower directly cooling the lamp and a larger regular fan that circulates air through the entire unit) are operating and clear of debris.

Once you have done that, then look for the REAL issue. With the front panel (i.e.the panel with the hole for the lens) removed and looking into the projector from the front examine the metal heat shield on the right side above the lamp. In my unit, because of years of service and heat, the aluminum lamp housing had deformed slightly, tilting this sheet metal heat shield directly INTO the air stream from the fan. This restricts the airflow enough to reduce cooling capacity. This metal shield should be high enough above the lamp to be TOUCHING the plastic case. If it is bent down and is halfway into the air stream then it restricting the exhaust airflow, causing the overheating.

Fix: Bend the heat shield back up so that it is not in the exhaust airflow. It must be ABOVE the airflow, protecting the plastic case from the heat of the lamp. This simple remedy fixed the issue for me. My projector has been running 2-3 hours a day for 10 days now with no banding issues at all. That's it. Simple fix.

My EP739 never got to the point where it actually shutdown due to overheating, but the root-cause may be the same. First thing you must do is clean out any dust and debris that may be restricting airflow. If that doesn't help then read-on...
My Optoma EP739 started exhibiting color-banding and strong color shift after years of great service. After trying other suggestions that didn't work, here is the FIX for my unit. I have not seen this posted anywhere else.

Problem: After 10-20 minutes of use, color-banding and then a strong shift to purple/green with almost no red. If the unit is turned off for 5-10 minutes to cool and then powered-up again the problem goes away, only to come back in another 10-20 minutes. Enabling the "High Altitude" setting in the Setup Menu helped for a while (a week or two) since it forces the main cooling fan run at high speed always, but then the problem re-appeared.


Reason: Overheating. The electronics are overheating. Like several people have suggested: First step: Open the unit up and blow-out/vacuum all of the accumulated dust. Assure BOTH fans (there is a small drum blower directly cooling the lamp and a larger regular fan that circulates air through the entire unit) are operating and clear of debris.

Once you have done that, then look for the REAL issue. With the front panel (i.e.the panel with the hole for the lens) removed and looking into the projector from the front examine the metal heat shield on the right side above the lamp. In my unit, because of years of service and heat, the aluminum lamp housing had deformed slightly, tilting this sheet metal heat shield directly INTO the air stream from the fan. This restricts the airflow enough to reduce cooling capacity. This metal shield should be high enough above the lamp to be TOUCHING the plastic case. If it is bent down and is halfway into the air stream then it restricting the exhaust airflow, causing the overheating.

Fix: Bend the heat shield back up so that it is not in the exhaust airflow. It must be ABOVE the airflow, protecting the plastic case from the heat of the lamp. This simple remedy fixed the issue for me. My projector has been running 2-3 hours a day for 10 days now with no banding issues at all. That's it. Simple fix.

bleed your brakes you possibly have air in the system, but instead of just bleeding one, bleed them all flush the old fluid out, make sure that when your bleeding your have a good eye one the resivoir to ensure that it doesnt get low, if it does and sucks air, youll have to do the process again. ideally youll need three people to do this correctly. person #1 to pump and hold the brakes. person #2 to monitor and add fluid to the resivoir, person #3 to bleed each brake. remember to bleed the brakes only after the person has pumped them up 10 full pushes of the brake, and then on push 11 hold the brake. then this is the time you would crack the valve to bleed the brake. the person in the driver seat will notice the brake goes to the floor. thats when you close the valve and do this again (pumping them up, holding , and then bleeding them), this is when the person monitoring the resivior will be adding more fluid. id do this to each brake 3 times to ensure all the air is out.

take the lamp out, there is a fan directly looking to the lamp... clean it with a compressor. and after that at the menu of projector there is a place called 'High Altitude'. turn it on. And it'll be fine...

try to replce your VGA cable. And also resit to factory default.

These units have many safety interlocks. First make sure that all of the doors that you opened are replaced correctly. If not, the interlocks will prevent any power from getting to the unit. Update this with what you find.

Dan

You need to open the top lid of the DVD player and you'll notice 2 more screws. Those need to be taken out. Then the lid will lift off the base. You'll then need to undo a couple of the wires to completely remove the lid. After this, you will have to remove the silver lid inside to gain access to the color wheel. It's pretty simple. Assembly is reverse.

I solved a similar problem by putting a small battery operated fan blowing directly into the IN vent (on the right side of unit). This completely takes care of the issue.

Now, I wish I knew what the real problem was so I could fix it...

i have the same projector with same problem. i called optoma direct and ordered a new color wheel. it was relatively easy and came in about a week. the phone no. is 408-383-3710

Sounds like the same problem i had recently, Take the front off, (its safe so your ok) You will see the 3 lenses which are ajustable, Just keep adjusting 1mm at a time until it solves this, Took me about 45 mins to get it perfect, Persist and you will get there!! Hope this helps