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  • Crown CE 1000

    I've got a Crown CE 1000 power amp that goes into protect mode when the speaker is plugged in. The relays are recycling continuously. I’m also not getting any voltage readings on the output transistors on channel 1. This amp has been discontinued so replacing the whole mainboard is out of the the question. Any thoughts or ideas? Thanks!
    Attached Files

  • #2
    First of all, there where about 5 or 6 versions of this amp.
    You have to be sure that the schematic that you have is correct.
    The Crown service manual walks you through what ground connections to make if the board is removed from the chassis.
    If you do not have the SM, go to Crown's site & get it.
    I am confused as to how the Ch1 output transistors can have no reading.
    The collectors of the NPN (MJ21194) transistors are connected to the +85 volt rail. So a reading can be had on the case.
    The emitters of the PNP transistors are on the -85 volt rail. A reading here will require that you flip the board over.
    What skill level do you have?
    These amps are a real challenge to repair.
    The board is a real pain to remove from the chassis.
    Most of the components are surface mount.

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    • #3
      A bad speaker, or a bad speaker cable, is the first thing to eliminate.

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      • #4
        Here is the link to the schematic set: http://www.crownaudio.com/pdf/legacy..._serv_revd.pdf
        You will have to wade through & find your board number.

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        • #5
          FWIW: If you're repairing this for a customer, be careful. These amps can be had for 2-3 hundred dollars on the web. Most guys don't want to stick a lot of money into them and like Jazz P. stated, they are a pain to repair. Very few of these that come into my shop are actually repaired. The customers just don't want to pay for the parts and time it takes to get them functional. You may want to just quit while you're ahead or at least give the customer a head's up on what you think it might cost before you sink a lot of time into it.

          Of course there will be those who disagree, but in my view, this is a disposable amp.
          "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

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          • #6
            I didn't realize there were that many. According to what I see on the chassis, it just says CE 1000. I went to their site to download the sm. I've never come across this amp before. I will send another schematic and hope that will help. I'm used to checking voltages on the casing of the transistors. Well I guess in this case, it's different. I haven't been doing electronics repair that long. Maybe about 5 years to be honest. I have an electronics degree, but been a computer/network field service tech most of my career. You're right, these amps are a real challenge. It's hard trying to probe any voltages on the circuit without it going off like a shotgun. Surface mount components, I usually don't waste time with that. I just wanted to know if this amp can be salvaged or needs to be condemned.

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            • #7
              Yeah, you're right. It is starting to get to that point.

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              • #8
                I have repaired a few of these amps.
                Sometimes it is something simple.
                Other times it is not.
                The worse one I had was pretty toasted on one channel.
                Way too much surface mount stuff was blown on the underside of the board .
                I got it working.

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                • #9
                  My hat is off to you guys who are willing to work on SMD electronics. I don't think they're worth the effort so I steer clear of them.
                  "Stand back, I'm holding a calculator." - chinrest

                  "I happen to have an original 1955 Stratocaster! The neck and body have been replaced with top quality Warmoth parts, I upgraded the hardware and put in custom, hand wound pickups. It's fabulous. There's nothing like that vintage tone or owning an original." - Chuck H

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                  • #10
                    Originally posted by Jazz P Bass View Post
                    I have repaired a few of these amps.
                    Sometimes it is something simple.
                    Other times it is not.
                    The worse one I had was pretty toasted on one channel.
                    Way too much surface mount stuff was blown on the underside of the board .
                    I got it working.
                    I agree Jazz P and should clarify. I didn't mean you shouldn't pop the hood and have a look. It may be something simple like you said. All I was saying was that it's easy to get in over your head dollar wise on one of these, especially given what they go for. Still, it would indeed be stupid to not at least have a quick look.
                    "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

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                    • #11
                      Someone gave my brother a dead CE2000 that was doing something fairly similar. It turned out to be a known issue with some of the surface-mount parts in the protection circuit. It started working after I replaced those, pain though it was, since I'm not that experienced with surface-mount soldering. Crown had some good troubleshooting and field upgrade tips in the CE2000 manual.

                      Most of what I've read about the CE series amps is that they're not nearly the equal, in terms of either reliability or sound quality, of their ancestors, the Micro and Macro Techs. I've got a Macro Tech 2400, too, and I can confirm that it's much closer to serious Hi-Fi than the CE2000.

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