Crown CTS 8200 all fault

[greatpopcorn]

Our theatre's 8200 will work for about 15 min, and then click like a relay has activated and all the ready lights go off. Then, it clicks every three seconds for about 2 minutes and every time it clicks the ready lights flash. Then all the fault lights turn on.

This is happening on every channel at the same time, and from what I understand, the channels are fault isolated so this must be something in common to all, like the power supply.

We've sent it to be rebuilt and it came back, worked for a month, and started doing this again.

Can anyone give us a nudge as to what would cause this?

 

[rwhealey]

Three questions: Did you send it to Crown or an authorized service center to get fixed? Did they fix something the first time? Does it do this if you have it hooked up to different speakers/wiring? Are there other CTS amps in the installation that work fine?

If you have isolated the problem to the particular amplifier and not, say, a short in your wiring or overheating in your amp room, then I would box it up and send it back where it was repaired. Any reputable shop should stand behind their repair lasting more than a month. If they don't, time to start looking at an equivalent QSC amp...

 

[greatpopcorn]

We have not pulled all the analogue inputs/outputs off of the amplifier yet, but that would be an excellent point. If those are gone and the amplifier still misbehaves, it is something inside the amp for sure.

EDIT: The overheating is not an issue, the other CTS amps work just fine (they are 2 channel amps).

 

[FMEng]

I get very curious when you just throw out a statement about overheating. Different models would have different temperature trip points, and different locations in the rack are subject to different temperatures. A failure that happens x minutes after turn on strongly suggests a THERMAL problem.

Take the unit out of the rack and test it. If it runs OK, consider whether the rack is excessively hot or preventing proper exchange of air through the amplifier. For example intake air cannot go in, if there is no place for exhaust air to go out of a tightly enclosed rack. It isn't uncommon to see racks that are built to be a vicious circle of air flow, with no actual cooling going on. Also observe whether the amp's filters and heatsinks are clean, and whether the units fans appear to operate normally. Fan failures are pretty common with older or mistreated equipment.

 

[greatpopcorn]

So, the airflow is front-to-back on these models, but regardless of that both sides are heavily air conditioned independently and both are working. However, your fans and filters bring up an excellent point, and I will look at that when I get back into the space.