Sony TA-VE170 Cooling Fan

The fan appears to be the same as that used in laptops and computer routers. It is a three-pin device consisting of ground, +12 V, and an rpm signal. This fan provides the rpm signal to the main microcontroller. If cooling the fan fails, then the microcontroller initiates the protect mode routine to prevent the amplifier from starting.

The fan used in this amplifier is the Sunon GM1204PKV3-A F.B221, and it is a 12 V DC fan rated at 0.6 W, and made in Taiwan. This one uses the magnetic leviathan system for the brush drive. This fan design is very common and used in computers. A generic fan that is 40 mm × 40 mm × 20 mm in size, and 12 V DC should work, providing it is a three-wire system with a compatible rpm sensor wire.

I managed to find a couple where even the terminating socket and wiring scheme were the same, and it appears to be almost an industrial standard in the computing industry. It is worth noting that one cannot use any fan because some fans have a built-in driver IC, whilst others use a transistor in an open collector configuration. However, most of these fans provide a square wave output for the rpm signal.

The colouring scheme of the three-wire fan follows a standard. The black wire is ground, red wire is +12 V, and the yellow wire is rpm signal out.

As you can see from the profile, the thickness is 20 mm.

On my amplifier, these holes were completely covered with dust and the fan was struggling to maintain the airflow.

When the airflow is diminished, it cannot maintain the heatsink temperature within acceptable parameters and this then triggers the protect mode. I was also finding that the fan was spinning for longer periods.

As well as these holes, there are also some more on the other side of the heatsink.

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