Film-Tech Forum ARCHIVE: CP500 stuck in bypass but no light

This is topic CP500 stuck in bypass but no light in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Kieran Hall (Member # 10268) on 11-06-2018, 09:41 AM:

Hi everyone

The gremlins plaguing our CP500 are back again it seems. After our recent Harry Potter marathon (which is the first time in a while it's been powered on for 24 hours), we powered it on a few days later and it appeared to working normally (the bypass light was not on and the lights on the Cat 682. were illuminating normally), but was stuck in bypass.

We put on the pink noise and left it for a while, and the noise cut in and out a few times with the accompanying click of the bypass relay each time. We replaced the Cat. 682 and nothing changed, but after doing a brain dump with Load500, replacing the Cat. 684 mainboard and restoring the dumped config the issue now seems to be resolved. We swapped back and forth a few times and the fault followed the old mainboard.

Anybody have any ideas on how/if we could repair the old Cat. 684? It'd be nice if we could keep it as a spare if it's just a case of replacing a few components on the board.

Thanks,
Kieran

Posted by Ken Lackner (Member # 1002) on 11-06-2018, 10:27 AM:

Yep. Cat. 684 is almost always the culprit in cases like this. I've replaced several over the last few years. Check with Sam Chavez (who is a member here and hopefully will see this) at BACP to see if he has one he can sell you. I wouldn't know where to start looking if you wanted to attempt field repair.

EDIT: I just noticed you're in the UK. Hopefully you can find a dealer in your area that stocks these so you won't pay as much in shipping.

Posted by Kieran Hall (Member # 10268) on 11-07-2018, 06:56 AM:

Hi Ken, thanks for letting us know that the fault makes sense! We were questioning out sanity a bit wondering why a mainboard fault hadn't broken more things and wondering if the Cat. 682 was going to have a nasty surprise in store for us later. It held out for the show last night too, so I presume (fingers crossed) that we're OK for now.

I think most of the dealers around here junked the bulk of their film equipment, but we'll ask around!