Optoma HD70 overheating--troubleshooting... - AVS Forum
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post #1 of 8 Old 02-27-2012, 05:37 PM - Thread Starter
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Hello all,

I am posting here for advice. I have been having trouble with my Optoma HD70 for quite some time now. The unit will work fine for a seemingly random period of time (sometimes only 10 minutes, sometimes an hour or more), and then it will crap out.

When I say crap out, the picture will flicker in color. The flickering will get faster, then the unit will shut down altogether (usually associated with a high pitched whine). After shutdown, the error light will flash orange. I have to then unplug the unit, plug it back in, and power it back up. The symptoms will usually repeat after that.

I am almost certain this problem is temperature related. The reason I believe this is: these symptoms were persistent a few months ago. Then, based on advice I found on google, I set the HD70 to "high altitude mode," which is just a high fan mode, and it worked PERFECTLY for a month and a half or so. Now, the symptoms are back.

So, I have a few theories:

1. The fan is "bad." As in, not moving enough air... The fan does not sound funny at all, so I am doubting this...

2. Dirty: not likely, as I took it apart and blew the dust out of it twice since November.

3. Poor positioning: possible. The unit is very near a wall (behind it), and a bulkhead that's in place for an air duct... this may be an issue.

4. Old bulb? This one I hope you guys can answer for me... the bulb is well over the recommended 2000 hours... somewhere around 2700 I think. Do old bulbs overheat? I had planned to simply use this bulb until it absolutely no longer functioned. However, if a bulb replacement will fix this, I will purchase one now.

5. INSERT THEORY HERE THAT I CANNOT THINK OF!!

I set up an experiment to test these possibilities. I have a multimeter with a temp probe. The probe is stuck just inside one of the exhaust vents in the HD70, recording the temp of the exhaust air. I will, for a few weeks, record the temperature of that air when the unit either: 1. Flickers or 2. Fails.

See picture below for my setup.

I will also try other methods of cooling, such as very low room temp, and adding an external fan...

Again, I appreciate any theories/advice you guys can deliver! Thank you!

Dean

[IMG] IMG_20120227_201359 by deanwvu, on Flickr[/IMG]
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post #2 of 8 Old 03-05-2012, 01:15 PM - Thread Starter
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Test is pretty conclusive, guys...


The short of it is--the projector works great when I have an external fan aimed at it (and on, or course).

When the fan is on, the temp of the air exiting the exhaust stays around 135 F.

When the fan is off, the temp of the air is about 142 or so, and the projector fails at around 142-144 F.

So... I can either leave an external fan on it at ALL times when using the projector, or I can find some other way to cool the projector...

Should I get a new bulb? A new internal fan (I have no indication the internal fan is failing...).

Any advice??

Thanks!
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post #3 of 8 Old 03-12-2012, 12:06 PM
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When you took it apart and blew out the dust, did you carefully clean the color wheel?
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post #4 of 8 Old 03-12-2012, 07:42 PM - Thread Starter
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I did blow out the color wheel, and the area around with compressed air (thoroughly). I did not touch the color wheel in any manner.

I do not know the correct procedure for cleaning the color wheel.
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post #5 of 8 Old 03-12-2012, 07:43 PM - Thread Starter
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I've pretty much ruled out any problem except temperature...

Bottom line--when the projector is cool, the picture is great.

When it gets hot (around 140F, based on my temp probe location), it flickers now and again (flickers green). When it gets to 142 or so, it fails.
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post #6 of 8 Old 03-14-2012, 10:22 AM
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I think you're right that the problem is temperature related. My theory is that the color wheel is prone to overheating if it has any dust on it. I have read instructions of someone who cleaned a color wheel with a q-tip. Here is the link:

http://www.instructables.com/id/Disa...5-Clean-It-Up/

I also read on a different web site that the sensor(s) near the color wheel need to be carefully cleaned as well.

Might be worth giving it a try.
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post #7 of 8 Old 08-17-2012, 11:38 AM
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Hello,

My symptoms were the same with the picture flicker after about 15 min and then shut down. I have followed the step by step instructions to clean it out and make sure the color wheel is nice and dust free. This worked the first time I had this problem over a year ago. Now it's back so I did the same. This time when I plug the projector back in the lights all flicker like its's got a bad connection to the power supply.

My question is, does anyone know what could be causing this. I didn't mess with anything else other than a light cleaning. I have to push the power cord in and wiggle it then and only then will it sometimes light up with the ready light. I played it for a bit and no beeps, no warning, it just shuts off completely. I have no clue where to begin in fixing this. Yes I would love to just get a new projector but right now I just want to see if anyone has a fix for this..

Any advice would be greatly appreciated!! Thx.
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post #8 of 8 Old 10-26-2013, 10:41 AM
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Any luck?

HD70 - Brand new bulb, Brand new Fan, Brand new color wheel.

Yet it shuts off after 15 minutes due to temps.
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