Originally Posted by ashyt16
If you look at the pic below you will see a sensor in the middle. The thing with 2 black wires running to it. This is a temp sensor, I think there is another near the lamp if memory serves correct.
During my repair I accidentally forgot to reconnect this and it caused the pj to shut down similar to yours.
I would look at maybe replacing the sensors
Thank you, don't think I've come across that one yet! There is for sure, another temp sensor (a thermistor) on a tiny green circuit board, screwed to the outside of the lamp well, near the front. I verified it's a temp sensor (the resistance drops with heat and increases as it's' cooled off).
That said, I think I found my problem
. As I noted above, what I was finding was that the large, black, axial, front exhaust fan, the one that's open to the lamp well, and blows out the front of the projector, was not turning on with the rest of the fans during startup, and remained off, even once the PJ shut off the lamp, and would flash the Temp light. I wasn't sure if this was normal or not. I thought maybe the PJ kept this fan off during startup to let the bulb warm up quicker?
I have since found out, that is not normal
. Last night before I tore apart the projector again, I decided to try firing it up first... and it worked! Immediately, first try. I noticed that the front exhaust fan was on though, and came on with the other fans.
I tried it a few more times with the lamp out, and it worked just fine, so I put the lamp in, tried a few more power cycles with the lamp in, still worked great.
So I took it to my Theatre, hooked it up, aligned it etc, worked awesome. I then continued to use it for about another hour, during which, as I was watching a DVD, it suddenly and inexplicably, shut it self off, and put the fans into high speed. This is the same thing it did before I started trying repairing it.
As I tried to turn it back on, it once again, did the same start-up behavior. About 5 seconds after turning it on, it'll turn itself off and flash the temp light.
I can only assume, that the front exhaust fan in question is flaky, and failing
. The fan is a 3 wire fan, so it's likely that it has a tach signal it reports to the motherboard to say if it's running or not. My guess is, it stopped running, the mobo knew that from the tach signal, and turned off the PJ to prevent overheating. And I bet it's not starting up again with startup, thus it won't finish booting up.
Unfortunately, that fan looks like a nightmare to get out. It doesn't seem to be removable from the lamp well area, there is plastic covering the corners. And it looks like to remove it from the front, you'd have to turn it sideways and pull it out. I gotta take a look again.
Anyone replaced or removed this front exhaust fan? Any tips?