Sign in to follow this  
Followers 0
wolff46

crown cts 1200 pip-bby amp hum and clip

7 posts in this topic

I have a crown cts 1200 that when it is powered with no input, and with one 8 ohm speaker connected to either ch 1 ch2 or bridged I get a steady level hum, like a ground loop. Also the ch 2 clip light will come on and stay lit. Sometimes giving it a firm tap will blink the clip light out . Any suggestions on troubleshooting? I have the board out and have inspected solders as best I could. Have a multimeter as my only diagnostic device

Share this post


Link to post
Share on other sites

Hi,

Check and replace C933 (change from a 470UF to a 560UF 35V).

Also, check U22 regulator (+15V reg, 7815) under Ch2 silpad. The input to the regulator should be around +18V.

Alain

Share this post


Link to post
Share on other sites

Is 14.92V on the input or the output side? If it is on the output side then the regulator appears to work fine. If, on the other hand, this voltage is the input voltage to the regulatopr, then we have a problem! Can you do major troubleshooting? You mention you have only a multimeter... If at all possible I would send the amp to our favorite Crown authorized service center. You will need to remove the main board from the chassis and probably have to do some unsoldering. Have you checked and measured C933?

Alain

Share this post


Link to post
Share on other sites

I'm not sure which side it was on. Ordered the parts should have them replaced tomorrow. Will let you know how that goes. Thanks again for your help.

Share this post


Link to post
Share on other sites

Replaced the voltage regulator (got a 56 uf cap instead of a 560 so put the old one back in) now I'm just getting a thermal warning

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0