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We do not repair any products other than our own.
We are more than happy to repair our products but please get in touch with us before hand and also when sending any parcels back to us to ensure you have a letter with the problems encountered and any checks you have carried out along with contact details, ideally a phone number but at the very least an e-mail address.
With controllers the MOSFETS are the most common thing to go, this is not because they are a weak or low quality component but simply because it is these which provide the current to your motors. Please see below for some examples of reasons for MOSFET failure.
Another commonish problem we get is the controller only selecting one direction (it will also select this direction in neutral) this is down to the DIN plug being forced 180 degrees out of line, it doesnt do it easily but it can be done, this blows a transistor in the little board we use to prevent you being able to change direction whilst moving. This is easily repairable, but almost 100% of cases where this happens is where the controller is tucked away in a loco and the operator is blindly pushing the handset cable in. We solve almost every case by adding a plug to chassis extension lead and mounting the chassis socket in an easily viewable position
When MOSFETS fail it is normally down to two reasons, a short circuit or excessive overload for a prolonged period of time. If a controller seems to keep failing then likelyhood is it is not your controller but a problem external to this, it just happens that the controller is the item which suffers.
It is possible to hazard a guess as to the cause yourself, we can normally say to within a high degree of accuracy what the fault was when we actually check the controllers, If the MOSFETS (these are the little black squares that overhang the circuit board and are bolted to the box) have a burn mark around them it is normally an overload, if they are cracked with very little burn marks we can normally say you have had a short circuit.
Among other things the cause for overloads and shorts are as follows:-
loco geared to fast - this causes high currents for extended periods of time.
Low battery voltage - causes the MOSFETS not to trigger properly resulting in very serious burns.
stray wire in terminals - this can either cause a direct short (only one strand touching the other contact can cause a £180 controller to fail) or if it is a high resistance then it will allow current to pass through it increasing the controller output current for extended periods of time.
Short in the motor - We have recently come across a number of 1HP motors (not our own) that have had problems with the field windings shorting. This may not be apparent for years or it may happen straight away, it all depends on the position (and the number) of the motor when power is applied. If the field is in exactly the right position it will cause a short circuit, if however another motor is on it may move the faulty motor just enough before the current goes too high.
Chassis being used as 0v - This in itself is not an issue as our controllers are isolated from the chassis. however the same 1HP motors as listed above have been known to have the brush gear move and contact to the motor bodym essentially meaning that the motor output on the controller is connected to the battery -ve, this will cause a short circuit effect and will destroy MOSFETS.
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Our Vision is to offer the best products and services to our customers. To always exceed customer expectations resulting in customer delight. Our mission is to provide highest possible quality at the right price.
