SC 900, radio defective

Hello moose driver, have never had Probs. with the SC 900 (V70 I, ́97) but now the radio, i.e. the station search run (scan) does not work anymore and it is not a single transmitter to receive. Cassette and CD play perfectly. It rushes in the boxes during radio operation. fuses, voltage supply etc. everything ok. Have already checked all plugs, power supply from and again jammed and SC 900 by means of CODE again activated – no change. Presumably that the radio receiver or antenna / antenna amplifier could be the cause. My wife spoke of wobble contact as it was running from time to time. How and what can I examine now, or does anyone else have any other ideas?