Christie CP2000-X Interlock System Failure

[Jay Glaus]

Hi everyone,

So I have a CP2000-X that is having an interlock issue. It was purchased used a few years back. When it came, it already had one of the interlock switches bypassed. Over the years others have failed and we've bypassed the rest of them. It's not the best practice, I know. We've always had it on the list of things to fix but always have had another pressing issue to deal with at the time. But enough of excuses...

Recently, it has developed an intermittent problem with the interlock system. Occasionally, when you go to strike the bulb, the interlock system with stop it and throw a code for the lamp fan. Not only is the lamp fan working, but it's interlock switch has been bypassed almost a year ago, and has checked out with full continuity to the board. So that is telling me that the problem lies in the board?

What do you all think?

[Steve Guttag]

How are you bypassing the interlocks? Are you tying them closed with a zip tie or are you physically cutting/shorting the wires or using male/male push connectors? The problem with continuity checks is that you are talking about VERY low currents (a problem with using electro-mechanical switches to begin with post-ROHS). You may test good all you want but it has no bearing on what the device (in this case your Ballast) is actually interpreting it. I'd start by going to the ballast DB9 connectors and cleaning them with Deoxit (both sides). It is the Ballast on the Christie that ultimately determines if it sees an interlock issue and throws back the "interlock open" nuisance.
.

[Dave Macaulay]

Those Christie ballast communication cable connectors regularly cause problems and reseating usually solves them temporarily. Cleaning the pins at least is helpful, cleaning the female contacts is not so easy. I've been putting "Stabilant 22" contact enhancer on connectors and circuit board edge connections. No real data on how well this works but I havdn't noticed any treated connections causing trouble again afterwards.

[Jay Glaus]

I'm physically cutting and shorting the wires a few inches from the connector on the board. I've tried reseating and cleaning, and nothing seems to work. It will work randomly and fail randomly.

[Steve Guttag]

Seriously, go after the ballast connectors (DB9). I've toyed with making short jumpers using gold contact DB9s to minimize the oxidation and also to make exercising them easier, plus avoid the thumbscrew/screwlocks. You have the "X" version so things are brought to the outside, which is easier to get to, normally.

[Marcel Birgelen]

It's good the DCI police isn't listening, tampered interlocks won't score you any karma points. :P

But, you'd say that if you physically short the wires a few inches from the connector, this should be sufficient to always register as "closed", especially if you didn't just twist them together and left them hanging out there, waiting for oxidation to strike. Those are simple contact switches, you'd say they're on +5 or +12V and a few mvolt more or less shouldn't make a difference in how they're read.

[Bruce Cloutier]

Couldn't hurt to actually use a volt meter to see what is what.