If your IC-756PRO’s receiver has lots of noise, with crackles and sweeping heterodynes, especially noticeable on AM, it may be due to a faulty electrolytic capacitor in the noise-blanker circuit (C287 on Main Unit). I’ve seen this happen to several 756PRO’s, and replacing the capacitor solved the problem.
Note: Icom used a few different values for this cap. In the original PRO, C287 is usually 22uF (although the service manual says it is 100uF). The PROII service manual says it’s 47uF. So I’ve been using 47uF as a replacement.
NOTE: If you don’t have the skills or equipment to work with static-sensitive surface-mount components, please leave it to an experienced technician.
Mike Nadeau – N1EQ
March 18, 2009