Film-Tech Forum ARCHIVE: CP45 odd problem

This is topic CP45 odd problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Dave Macaulay (Member # 813) on 05-01-2009, 08:04 AM:

Found a CP45 in bypass, with no info as to why. Returned to normal, and it wouldn't come out of NS. Removed and replugged the cards, and it would switch formats according to the panel LEDs but still just play NS. Then it started working normally. I suspect it will have to go back for a $$$ repair at Dolby, but does anyone have any ideas what's wrong? The logic section is the likely culprit but why would it change behaviour?

Posted by Tony Bandiera Jr (Member # 2365) on 05-03-2009, 01:19 AM:

Some guesses:

Got hit with a power spike that rattled the logic;
Component in the logic section is going bad;
Possibly a voltage spike got impressed on the automation lines;
Automation was locked up in NS format;
and finally the CP-45 wasn't one of Dolby's best...

Posted by Louis Bornwasser (Member # 3063) on 05-03-2009, 09:59 AM:

Early units the large board could sag and make contact with the case of the nr board (ground).

Easy solution, don't clip the board fully down. If this is unacceptable, superglue a poker chip on top of the nr module.

Later units solved this problem (Best solution, get new clips with a slightly longer normal position.

This was a "Smart killer" when it was introduced, selling for little more than the nr card. While not Dolby's best, it was reliable and very good for the money until they started raising the price. Louis