I have a crown CDi1000 amplifier and it seems the power supply is the issue. When the power switch it set on, nothing happens. No lights, no fans. Pulled the cover off, and check the primary fuse. That was fine. I found one area of the board that is suspect. The board was browned as if it had gotten warm/hot in that area. I checked the 3 transistors in the area and they were not shorted. They were a MPSW42 NPN-transistor. There were a couple of resistors in the same area that looked like they had gotten warm, but tested fine as well. I probed around and found that all the larger size caps have a DC voltage on them as well.
At this point, I don't really know where to go to find the issue. It seems obvious that it is a power supply issue, but could a failure in the amplifier down line be the issue? Any help would be appreciated. I've attached some pictures of the power supply section. Let me know if I additional pics would help. Thanks!
Picture 1 : The area that the board was darkened
Pictures 2-4: Power supply section.
Link to transistors I tested
http://www.onsemi.com/pub/Collateral/MPSW42-D.PDF
At this point, I don't really know where to go to find the issue. It seems obvious that it is a power supply issue, but could a failure in the amplifier down line be the issue? Any help would be appreciated. I've attached some pictures of the power supply section. Let me know if I additional pics would help. Thanks!
Picture 1 : The area that the board was darkened
Pictures 2-4: Power supply section.
Link to transistors I tested
http://www.onsemi.com/pub/Collateral/MPSW42-D.PDF
Attachments
The service manual can be found here:
CROWN CDI1000 SCH Service Manual download, schematics, eeprom, repair info for electronics experts
Although the PSU board might be a slightly different revision, that group of resistors seems to not be laid out identically.
CROWN CDI1000 SCH Service Manual download, schematics, eeprom, repair info for electronics experts
Although the PSU board might be a slightly different revision, that group of resistors seems to not be laid out identically.
Awesome! I tried looking for a service manual, but google never dug that up. Thanks!
I wasn't sure what you were talking about the resistors not being laid out the same until I looked at the manual. Hopefully all the connections are the same. This will help me work my way through the amp some more. Thanks a bunch!
I wasn't sure what you were talking about the resistors not being laid out the same until I looked at the manual. Hopefully all the connections are the same. This will help me work my way through the amp some more. Thanks a bunch!
Hi, I am working on the same model and incurring a similar problem, however it does power up but audio output levels are low and this area also runs hot. I do know that Crown revised the C196 cap to 63 volts rating, but so far the issue is eluding me. Did you ever get yours running properly?
thank you
John
thank you
John
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