Pioneer SX-450 Left channel dead. Cleaned dirty mono switch. Also crackling on switch on for approx. 30 seconds with panel lights dimming and brightening alternately. Cleaned On/Off switch. Unit OK.

Realistic STA-2250 Unit had been left out in the rain! Everything cleaned and visually checked. After a few days in my airing cupboard unit powered up. Everything OK except on FM. On weaker stations the stereo indicator and tuning LED flashing in time with the music. On strong stations no LEDs at all. With FM mute selected the LEDs would light on switch on and both channels would be OK. Then after approx. 1 minute the LEDs would start to flash and then right channel would fail - then left channel. The unit was left in this condition and freezer spray applied to I/C 101, a A1231N device. Both channels and LEDs came back on until freezer wore off. I/C 101 replaced. Unit OK.

JVC R-K20L Right channel dead. Signal traced right up to output pair of transistors 2SD716 & 2SB686. Both output transistors replaced. Surrounding components checked. Unit OK.

JVC R-K20L Left channel distortion. O/P bias voltages checked - 0 volts. Trimmer pot . adjusted - no change - o/c.
R729 10R found burned but still measured OK. Adjacent transistor Q719 (2SA965Y) found o/c. R729 and Q719 replaced and bias voltage adjusted to 10mV. Unit tested OK.

B&O Type 2101 No M/W, L/W, S/W. Also no tuning meter movement. FM and line sources OK. Transistor BC149 in meter circuit found B/E open. Transistor replaced - unit OK.