Have been meaning to try this for a while. However first a word of warning. Have only modded one of these, seems to work, but there could be problems yet to find. This is not an easy mod to do physically.
This mod can be viewed either as a way of repairing a failed Saloon board or as an upgrade to the output stage. I suspect most failed boards have one or both of the output mosfets failed.
The device I have chosen to fit as a replacement is the one used by Scalextric in the early Powerbase's, the ZXMC3A16D. If two of them were nearly good enough to power 6 cars, one should be well over the top for one.
The output mosfets are the small black devices marked N02 & P03. First these need to be removed. Apply a soldering iron to the two connections on one side & when the solder melts flip up the device with a screwdriver, now desolder the final connection and remove the device.
To fit the device you need to slightly splay pins 1 to 4 in an outward direction to make them fit the four pads marked in red in a row on the picture. Be very careful not to bend the leads too close to the body of the IC and only tweak them just enough to reach the edges of the pads. The 4 Drain connections, pins 5 to 8 are then connected to a piece of tinned copper wire and the ends bent and soldered to the two remaining connections.
So thats it.
Have never been able to find a spec for the P03 & N02 devices. I assume they are mosfets, but have seen Beppe post that they are transistors?
However here is a comparison between this mosfet and the DF2C03 used by Slot.it in their new decoder.
As you can see it compares favourably in all respects.
The disappointing part is that in testing, I modified a Takara module for ease of swapping, the performance seems identical to the original. This is confirmed by on track performance and by measuring the voltage at the motor.
I therefore expect the gain to be with beefier motors and hopefully that it will not expire.
Ideally need a few people to try this and report back. Very little to loose if you have some failed Saloon boards. This will of course also work with the F1 board.
Farnell part nos for the ZXMC3A16D is 756-4953
Rich
This mod can be viewed either as a way of repairing a failed Saloon board or as an upgrade to the output stage. I suspect most failed boards have one or both of the output mosfets failed.
The device I have chosen to fit as a replacement is the one used by Scalextric in the early Powerbase's, the ZXMC3A16D. If two of them were nearly good enough to power 6 cars, one should be well over the top for one.

The output mosfets are the small black devices marked N02 & P03. First these need to be removed. Apply a soldering iron to the two connections on one side & when the solder melts flip up the device with a screwdriver, now desolder the final connection and remove the device.
To fit the device you need to slightly splay pins 1 to 4 in an outward direction to make them fit the four pads marked in red in a row on the picture. Be very careful not to bend the leads too close to the body of the IC and only tweak them just enough to reach the edges of the pads. The 4 Drain connections, pins 5 to 8 are then connected to a piece of tinned copper wire and the ends bent and soldered to the two remaining connections.

So thats it.

Have never been able to find a spec for the P03 & N02 devices. I assume they are mosfets, but have seen Beppe post that they are transistors?
However here is a comparison between this mosfet and the DF2C03 used by Slot.it in their new decoder.

As you can see it compares favourably in all respects.

The disappointing part is that in testing, I modified a Takara module for ease of swapping, the performance seems identical to the original. This is confirmed by on track performance and by measuring the voltage at the motor.
I therefore expect the gain to be with beefier motors and hopefully that it will not expire.
Ideally need a few people to try this and report back. Very little to loose if you have some failed Saloon boards. This will of course also work with the F1 board.
Farnell part nos for the ZXMC3A16D is 756-4953
Rich