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  • Crown CE2000 issues

    Greetings all!

    I have a Crown CE2000 currently in my possession that has a few issues. I'm not much more than a dabbler when it comes to repairing electronics; I can solder and and replace components and test some simple things such as resistors, but I'm not very knowledgeable when it comes to more advanced things and usually know my limits.

    I'm posting here to see if anyone who might be familiar with these amps can offer a little insight on the issues I'm having with this amp. (more or less seeing if repairing it is within the realm of possibility of my skills, or if I should take it so someone else, and if it is even worth it.)

    First issue:
    When I received this amp, there was already an issue with channel 2 in stereo mode. Upon turning up the volume, the woofers connected to channel 2 would just push out and buzz, and you would get static when turning the knob, and no output other than the buzz and static. It's not enough of a problem to trip the Fault light on channel 2; it clicks on just fine at powerup. I thought this may just be a dirty or bad pot, so I sprayed it with tuner cleaner to no avail, and later swapped the pots on the board around, and channel 2 still behaved the same, indicating that the problem was elsewhere. I also tried simply tightening the heat sink nuts, as I had found a thread on here that indicated this sometimes fixes odd problems from bad grounds, and that also did nothing. If the amp was put into bridged mode, however, channel 2's output merged with channel 1's just fine. I assume it's a pre-amp issue.

    I gave up on that issue and accepted the fact that until I got it properly repaired, the amp would pretty much be 1 channel at half the power (which was good enough for what we needed it for) or would function well in bridged mode if I ever got higher ohm speakers for it (2 4-ohm cabs came with it, and this thing is not rated to handle a 2ohm load in bridged mode; you can only run 2ohm in stereo mode.)

    The other issue:
    Then, 2 weeks ago, we had the amp at a show. It performed well, but at the end of the night when it came time to power down and tear down, I was distracted and wasn't paying attention to what I was doing, and unplugged my bass amp while it was still on and running through the PA with volume levels still up. (yeah, I know- PA first! It was a very dumb mistake.) This put a major THUMP through the system of course, and when I looked at the amp, I noticed that the channel 1 Fault light was now blinking, and there was no output.

    Between this site and another one, I found some excellent detailed threads about this amp's fault circuit (CE1000 included since it's similar). While they went far deeper than my understanding and skills, they at least gave me some insight on what is involved in the protection circuit, and makes it seem more likely that it's just one of the components involved in that, and less likely that the actual output chips for channel 1 got fried. However, I leave that up to you folks here to chime in on- most people tell me that big thumps like that are more likely to damage the speakers than the amp, but I really don't know.

    So far, for the channel 1 issue, one at a time I've replaced the C121 and C124 muting capacitors, and swapped the transistors at Q131 and Q131 with their channel 2 counterparts, and nothing has changed. The only additional things I can see that I could try swapping are the relays, and components U1, U2, C4, and C5. Other than the relays, I'm unsure if the rest I listed are even related to the output stage, or if they're just part of the general power circuitry, so I stopped there. I see that it's also possible that the little chips at U104 and U105 are bad, but I do not have the tools to work on surface-mounted stuff.

    So, any advice on those 2 separate issues above is appreciated. Even if it's beyond my skills, it will at least give me something to pass along to the technician that I may end up taking it to.

    And one last question: In the amps present state, I still have output on the channel 2 side if I switch it to bridged mode. Normally, you can't put a 2ohm speaker load on this amp while in bridged mode, but you can in stereo mode. Since channel 1's output is muted while in Fault mode, it would seem to me that channel 2 is more or less effectively functioning as it would if as though it was in stereo mode, with just it's own amp independently. If this is the case, would it then become safe to run the 2 4-ohm cabs out of channel 2 alone in bridged mode, in this crippled state?

    Thanks! :-)

  • #2
    You need a speaker cable wired up differently for bridge mode, correct?
    So if you have it set to bridge, but use standard cable plugged into ch.2 output, you should be fine down to 2 ohms. Only hitch being the phase will be reversed in relation to any other amps using the same input signal.
    Originally posted by Enzo
    I have a sign in my shop that says, "Never think up reasons not to check something."


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    • #3
      Hey, thanks for the reply! Sorry it took so long for me to get back on here.

      Yes, that is correct; Bridged mode normally requires different wiring on the speaker cables. I'm just using the banana clip plugs, one piggy-backed on to the other, wired normally. There will be no other amps using the input signal.

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      • #4
        Then you should be ok with the 2 ohm load. If the phase inversion becomes an issue, just flip the banana plugs over.
        Originally posted by Enzo
        I have a sign in my shop that says, "Never think up reasons not to check something."


        Comment

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