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Discussion Starter · #1 ·
Hello everyone,

I've had my 4805 for about 1.5 years, it has a little over 600 hours on it, as we use it mostly for weekend films.

We recently moved and it took me a couple of months before I got to assembling the home theater. I never had a problem with the projector (other than dust blobs) in the old house but at the new place.....

Most of the time, after powering up and striking the lamp, it shuts down after about two minutes. I get three blinks on the red led, manual says something about the lamp door. If I take the lamp out and replace it, sometimes it works, sometimes it doesn't. If I leave it unplugged for a few hours, sometimes it works, sometimes it doesn't.

At first I thought it was a power issue, this is an old house. So I unplugged or shut off everything in the house and again, sometimes it works, sometimes it doesn't.

Tonight, I took the manual's advice and unplugged the projector for one minute after unexpected shutdown (even though the lamp was still a little hot, uhhg) and it worked. I'm betting that this was a fluke however.

I carefully packed the unit in its original packaging when we moved and I moved it myself, again being very careful.

Is this a logic thing, or a circuit board issue? Could a pcb plug have come just a little loose during the move? Just thought I'd check with you folks before tearing into it.

Thanks for your time,

-Mac

PS: It may be Murphey's law at work here, it only works when I don't have time to sit and watch, never when we plan on using it.
 

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If the power is sketchy in the new (old) house, that could cause a problem.


Do you have a UPS you could plug it into just to rule it out?
 

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Discussion Starter · #3 ·
I don't have a UPS but I can take it to school. I teach at a fairly new campus so the power there should be good. However, I just don't think it's a house-wiring issue. Mostly because when the unit powers down (which is most of the time) it is always about two minutes after striking the lamp.

Thanks for the quick reply.
 

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Discussion Starter · #4 ·
Update:

Okay, it doesn't seem to be a house-wiring issue. My reasoning is absed on the fact that I can turn everyting in the house off and it still shuts down after two minutes or so. Also, when it works it doesn't matter how many appliances run. I even ran a space heater on the same circuit (I was feeling daring).

However, what does work is unplugging the unit for one or two minutes (after it prematurely powers down), and plugging it back in and powering it on. I realize the lamp is still a little warm and what that could mean.

Input anyone?
 

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Discussion Starter · #5 ·
"My reasoning in 'based' on the fact...."

"...I can turn 'everything' in the house off..."

Sorry for the typos, long day.
 

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you might want to clean the lamp filter.
 

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Discussion Starter · #7 ·
I've always kept the filter very clean. We have cats so I clean it more often than I should probably. But thanks for the suggestion.
 

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Once you get it powered on, run the lamp in high-power mode for a minimum of 8 hours straight.


If that doesn't fix it after a few days of running in this method, then it sounds as though you've got either a poorly-seated door/bulb or a fan issue, which is making the pj think it is running too hot. Check the fan output for proper airflow. The lamp shouldn't move even a hair once secured. The lamp door should also 'snap' into place.
 

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I believe that your problem is that the 4805 has two fans and only the one that cools the light tunnel is operating. When the fan that cools the bulb is not working, the 4805 will run for a couple of minutes and then die. This seems to be a standard failure with the 4805. Suggest that you open the unit (many threads on how to do this) and substitute an external power supply (4.5 Vdc) to power the bulb cooling fan all of the time.
 

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Discussion Starter · #10 ·
Is there any way to test for fan operation? Can I run the projector once opened?

What exactly does running the projector in high power mode for eight hours do, do you know? Does it reset the heat sensor or something?

I almost won a used projector on eBay last night, it had no lamp, a bad light tunnel, and no color wheel. It was perfect! Lol. However it went for over fifty bucks so i took a pass.

As far as the lamp fan not working, it "sounds" the same. I'll check it out anyway.
 

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Discussion Starter · #11 ·
Okay, for anyone reading this with the same issue (unit powers down after about two minutes, three red blinks) I have found the following to work.

As per spider696969's suggestion, I ran the unit in high power mode a about a half hour, when I decided to switch to low power mode. It worked. Now, every time I power down, I turn it to high power mode for a minute or so. Then the next time I power up, it's already in high power mode. I let it run in high power for just a minute, then switch to low power and watch my movie, again switching back to high power before shutting down. It does seem rather convoluted but it works. A couple of times I have forgotten to turn the unit off in high power mode but switched it to high power just after powering up, and this also works.

Now for the bad news; after all this power stuff, I now see the dreaded yellow stripe down the right hand side of the screen. It's not enough to interfere with the picture (yet) but the time is coming that I will need to disassemble, clean, and rebuild. I just wish we had a "clean-room" in which to do this. We have four indoor cats, lol. Oh well.

-Mac
 

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new user have the same problem right now. replaced the bulb and found the bulb fan not working. inspection found that there is a low pulsed tone comming from the projector and every time you here it the fan moves. removed the fan and tested withh enother power supply and it is working. anyone have any ideas?
 

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Discussion Starter · #13 ·
Update:

Okay, we didn't care for the house we were in so we sold it and bought an old farm house. Again, took us a couple months before building the theater but guess what...

The premature shut-downs are no longer a problem, go figure. Could be that (and I dscovered this after all the previous posts) was that the outet I had the unit plugged into was grounded to the main water inlet pipe rather than the fuse box. This old farm house has many updates including all new wiring with 12 guage grounded wire. Works like a charm now.

If anyone is having two-minute shut down issues, check your wiring or take it to a friends new-ish house for a test.
 
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