IMPORTANT – if sending the amplifier board DO NOT REMOVE THE HEAT SINK
Most of the earlier Technics pianos have a large, finned aluminium heat sink attached to one of the edges of the amplifier board. It is easy to identify as it is metal, silver in colour and has some transistors screwed to it. Very early models may also have a large amplifier chip screwed to the heat sink.
DO NOT REMOVE THE HEAT SINK!!
It is not necessary to remove it.
It causes more work for you.
It increases the risk of damaging the amplifier board when you remove the heat sink and when you come to refitting it.
The transistors, their solder pads and the printed circuit track are likely to be damaged in transit.
It is risky testing the amplifier board without the heat sink because there is nothing to keep the transistors cool.
It makes repairs difficult and unreliable.
If any components screwed to the heat sink have to be replaced, the heat sink is necessary to set the component in the correct position. Without the heat sink it is impossible to be certain that the component is at exactly the right height. If the height of a transistor is even slightly wrong, its solder joints will be put under stress when the heat sink is re-attached. This may cause the solder joints to crack or could cause the solder pads and track to lift or fracture. If this happens the amplifier will need repairs that will cost more than if the pads and track were undamaged.
SO … DO NOT REMOVE THE HEAT SINK!!
If you do, I will ask you to send me the heat sink and screws. Your repair will take longer while I’m waiting for the heat sink and will cost more because I will have to spend time refitting it.
E&OE