Tuning problem

[Stech]

Recently I've been having problem with my Technics SL-CH900 tuner/receiver. When i do the automatic tuning, the counter keep running (searching) nonstop. If fails to detect any station/channel. However i could tune to the channel's frequency manualy n it works but the 'STEREO' indication is OFF. Tried adjusting the antenna but it seems doesnt work. Pls help, tq.

 

[Donald123]

CCRT700 by any chance?

 

[jerryg50]

Recently I've been having problem with my Technics SL-CH900 tuner/receiver. When i do the automatic tuning, the counter keep running (searching) nonstop. If fails to detect any station/channel. However i could tune to the channel's frequency manualy n it works but the 'STEREO' indication is OFF. Tried adjusting the antenna but it seems doesnt work. Pls help, tq.

I have seen the stereo decoder IC become defective, and or other support components cause the fault you are describing. This decoder circuit also supplies the tuning reference for the receiver's AFC and AGC circuits. Without both of these references functioning properly, the automatic tuning is missing proper reference to know the zero cross-over point for its PLL (Phase Lock Loop).

An experienced service tech with the service manual and the proper test gear can track this down and replace the defective parts. The issue here would be the time involved more so than the parts cost. It can easily take a number of hours to troubleshoot this type of fault if it is not simply only the IC itself.


Jerry G,