This is topic CP-500 looking for Projector 2 in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=002296
Posted by Rick Long (Member # 213) on 05-21-2001, 12:32 AM:
It's been one of those weekends on call. The type where you go to a theatre to fix a fault, and hear the dreaded words "Oh while you're here.........". The complaint was "the sound drops out during the trailers" - CP-500, Ashely amps, C-E basement reader, ect... Naturally, this was mentioned minutes before showtime.
The feature, "Mummy 2" was run using Dolby Digital, and (as I suspected) some of the trailers were optical only.
A click test proved that there was no sound in either the 04 or 05 formats. After a quick check to ensure that the voltage output to the C-E preamp was correct, (LEDS in the sound-head were on), I opened the CP-500 panel.
It took a minute to register (in my mind) but I noticed that the 661 optical pre-amp was looking at projector 2 (yellow led). Problem was, that this was a platter booth with only one projector.
Powering the system down and pulling and re-inserting the 661 card seemed to clear the fault (now reading projector 1 (red led)).
Has anyone else experienced this problem and what causes it?
Posted by Randy Stankey (Member # 64) on 05-21-2001, 01:45 AM:
On the back of the unit there is a small jack that looks like a serial cable connector. This is the motor start relay connection. It is supposed to tell the processor which of the two projectors is running at any given moment. If there is only one projector it is supposed to have a plug installed in it that has a wire soldered across two of the pins.
If this connector becomes loose or the wire(s) come undone, the processor won't be able to tell which projector is supposed to be running. This is the first thing I'd check.
Posted by Pete Naples (Member # 761) on 05-21-2001, 02:54 AM:
There was a field buletin some time ago (sorry I forget the nmber), it related to CP500 Random change over in optical format. Basically soem CP500 will change over without being asked, and moreover, the front panel will not display the active projector correctly. There was a mod to carry out the remove software control of change over. That said, I'm pretty sure that it was only supposed to happen when the link that Randy mentioned was NOT fitted. ie a change over house, or where the change over was used to mute. Have fun!
Posted by Gordon McLeod (Member # 33) on 05-21-2001, 10:58 AM:
The link is for motor sense and that is for digital changeover the opticle is still independent of that
Posted by Pete Naples (Member # 761) on 05-21-2001, 01:05 PM:
Ae you are quite right Gordon, the only connection is that the optical change over connections are via the same backplane connector. Either something is shorting and causing our friends CP500 to change over, or the CP500 is doing it all on it's own, without being asked! It does happen, one of my installs suffered from this problem a lot until I carried out the mod in the aforementioned ( I still can't find the number) DOlby field bulletin.
Posted by Pete Naples (Member # 761) on 05-21-2001, 01:21 PM:
Seek and ye shall find....FB217
Posted by Randy Stankey (Member # 64) on 05-21-2001, 02:45 PM:
FB-217 Comming right up!
Posted by Rick Long (Member # 213) on 05-21-2001, 04:10 PM:
Really appreciate the help guys, thanks.