[Dr_C]

A while back I shared a general thread on repairing SSD decoders - focusing on replacement of the MOSFETs. Thiscan be found by following the link below:

https://slotracer.online/community/showt...2#pid35192

Meanwhile, the C7005 remains an import SSD decoder which is specially useful for retrofit into both saloon and F1 cars when space is tight.

Also, if used with cars with higher torque motors than found in Scalextric cars then upgrading some of the components may be necessary - for example when fitting into NSR models.

In this case there are two parts to the upgrade:

1/ MOSFETs

For the n-channel MOSFET I recommend replacing with the AO3434. Here you are replacing the part labelled NO2.

For the p-channel MOSFET I recommend replacing with the AO3407. Here you are replacing the part labelled PO3.

2/ DIODES

Here I recommend replacing the 1Amp silicon diodes with 3Amp Schottky diodes. These carry higher currents and run cooler.

I recommend replacing with Schottky diodes type PMEG4030ER - and of course you need 4.

Procedure:

I typically upgrade in two stages. First I replace the two MOSFETs and test for correct function of the decoder. I test motor control, braking and motor coasting.

I then replace the diodes and again test as above. Note the diodes conduct current in one direction only, so are polarity sensitive. The polarity is marked by a series of lines at one end of the diode. Make sure you fit the new diodes with precisely the same polarity as the diodes you are removing - and here some diagrams/sketches will help!

All being well, the job is now done! You now have a power upgraded SSD decoder.

Next post will show a couple of images of the C7005 after this upgrade.

Good luck!

c

[Dr_C]

   
Above photo showing replacement MOSFETs in place

   
Above photo showing replacement Schottky diodes in place

[steveaca]

Hi Dr_C,
   do you do repairs on defective SSD chips for other people ?

[Dr_C]

hi steveaca,

Thanks for the kind question. I guess in sharing posts on how to repair and upgrade SSD decoders I am hoping this information will help those electronics wizzes in various clubs around the globe to give it a try.

For anyone with electronics knowledge and soldering skills it’s not hard - but it is quite time consuming.

Meanwhile, do you have someone nearby who could assist?

c

[Dr_C]

As the AO3434 and AO3407 become more difficult to source - the readily available AO3434A and AO3407A can be used instead. These are current production versions.

c