Film-Tech Forum ARCHIVE: Dolby CP-55 bizarre wake-up?

This is topic Dolby CP-55 bizarre wake-up? 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=008039

Posted by George May (Member # 1060) on 05-30-2006, 05:09 AM:

Symptoms:

When switched on, my CP-55 goes straight into Bypass mode. If I then remove the Bypass mode fuse from the CP-50 power supply unit it switches to normal operation and works fine. Replacing the bypass fuse again causes it to go back into Bypass mode.

I've cleaned the contacts on the Cat 249 and Cat 250. It makes no difference.

I can live with it, but what's happening? Can anyone help?

Thanks

George

Posted by Steve Guttag (Member # 268) on 05-30-2006, 09:30 AM:

I'd be willing to wager it is your Cat 249 card. There is a circuit on that card that determines if all is okay with the main rails and if not, go to bypass. It, no doubt has an issue or possibly, one of the main power rails is indeed out of spec and it is properly trying to switch to bypass to get you to RXO the Cat 249 card. Which will probably need to be upgraded to the Cat 249A (a better card).

Posted by Richard May (Member # 2627) on 05-30-2006, 10:46 AM:

George, had the same problem and it was indeed the Cat 249 card.

Posted by George May (Member # 1060) on 06-02-2006, 06:58 AM:

Thanks guys. Steve, you win your wager. Replacing the 249 fixed the problem.

George