Christie projector error

[Peter Foyster]

During the winter months my system is only powered up once a week for 2 to 3 hours as the cinema, being outdoors, only operates between November and April.

I had an issue initially with the projector, a Christie CP200ZX which would simply show a red error light and could take a week or more of restarting before it would go into standby mode. This appears to be some sort of network communications error. I found that by booting up the DSSS100 and Show player first and then powering the projector, it would take only a few minutes for it to establish communication.

However, another error now comes up soon after the projector is turned on, being Exhaust Temp SFail. The temperature initially reads about 190° and then gradually reduces to normal over a period of about half an hour. All other temperature readings are normal.

Clearly the temp is not actually that hot when the projector has had no power for a week and the ambient temp is about 20° C.

I know nothing about i2C communication but suspect that there is something causing a faulty reading. This is not a major problem in itself as when the error clears and the projector is running there is no further issue.

It would be nice, however, to get an idea of how and why the error occurs, if anyone can provide a most likely explanation.

[Marcel Birgelen]

The communication between your server and the projector isn't I2C, but Ethernet, so this problem doesn't really sound related. Also, I doubt there is a problem with I2C communications if one temperature reading is off. A reading of 190° C is obviously excessive, you could fry fish & chips in that exhaust, so the most likely culprit is a dead or rather dying temperature sensor.

[Peter Foyster]

Thanks Marcel,

I was actually using software on a remote laptop to connect directly to the projector. According to the Christie manual, the error message for the SFail condition is "Sensor Failed By No I2C Communication".

If the sensor was dead or dying would it not produce the error at random times rather than always almost immediately after starting the projector? I monitored the temperature reading for over half an hour as it slowly indicated a gradual reduction down to normal.

The lamp was not on so there is no apparent reason for such a high temperature reading. There is a custom temp sensor on the exhaust output of the projector which reads under 20° and rarely reads above 40° when the lamp is operating on the hottest nights.

If I leave the projector on standby for a few days and then switch it on, there is no error. It seems to be only when powering the projector up from the mains that the error occurs.

[Marcel Birgelen]

If there would be no I2C communication across the board, a lot of stuff would have no readings at all. It also doesn't make sense to have a loss of communications, but still have a reading for the sensor. In the end, almost all cheap temperature sensors are thermo-couples of which the resistance is matched to a table or function to convert it into a temperature reading. So, something starting with an excessive reading and slowly stabilizing over time to me, feels like an almost clear indication the temperature sensor itself has failed, rather than something else. Also, replacing the temperature sensor should be a relatively cheap fix, much cheaper than any board replacement, that's why I would start right there.

[Peter Foyster]

OK thanks Marcel,

I will look into getting a replacement. It doesn't seem to be particularly urgent at the moment, though. Any idea where that particular sensor is located and if it is easy enough to get to?

[Marcel Birgelen]

I agree that the error most likely can be ignored for the time being. Keep in mind though, that the exhaust temperature isn't correctly monitored now and a failure of the exhaust fan could lead to actual overheating.

If it were a recent Barco, I could tell you how it looks like, but I haven't replaced an exhaust temperature sensor in a CP2000-ZX or comparable machine, but maybe someone else on the forum may chime in. It's most likely close to where the exhaust manifold connects and since it's connected to the I2C bus, I'd expect a very small board in the neighborhood of the sensor, connecting it to the bus.

[Leo Enticknap]

The projector's service manual should tell you where that sensor is. If you don't have it, you could try emailing support.cinema [at] christiedigital.com, and they'll likely send you a PDF of it. They could also put you in touch with a Christie dealer in Australia who could sell you a new sensor. Agreed with Marcel that it's likely above the lamphouse, in the neighborhood of the exhaust manifold.

[John Thomas]

The exhaust sensor is right up in there with the exhaust sail switch. Those temp sensors on the series 1 machines fail all the time these days. Since it's inside the lamphouse you need to be extra careful with the wiring when you replace that sensor because the wires get very crumbly over time with all the heat and UV.

As a side note, if you have a technician who does regular maintenance on that machine, ask him/her when the last time the PCM board battery was changed.