paul delany
Registered
Hi folks has anyone here ever done any repairs on revo recievers I fit one the other night and smelt a bit of smoke,,the loco will drive forwards but wont drive in reverse,I'm hoping it is just a blown mosfet/ transistor?
Faulty revolution reciever
- Thread starter paul delany
- Start date
Very possibly, but take a step-back.. Why did the transistor(s) blow?
If there was something that caused the motion to lock, will it happen again??
Every loco that comes my way for work. First-thing, it get's run forwards and backwards on DC, from a bench supply which has current and voltage metering. - This way I can judge how worn the mechanism is. What current it takes (no load) and, if I wish, I can stall the loco (or try to!) and see how much current will be pulled under an extreme fault.
No amount of alternative electronics, will compensate if there is an underlying problem with the mechanism.
You may 'just' have been unlucky, with a sub-standard component? But who is to say that once under load, the loco won't draw enough current to burn out more than just an output transistor.
Sorry, but..
If there was something that caused the motion to lock, will it happen again??
Every loco that comes my way for work. First-thing, it get's run forwards and backwards on DC, from a bench supply which has current and voltage metering. - This way I can judge how worn the mechanism is. What current it takes (no load) and, if I wish, I can stall the loco (or try to!) and see how much current will be pulled under an extreme fault.
No amount of alternative electronics, will compensate if there is an underlying problem with the mechanism.
You may 'just' have been unlucky, with a sub-standard component? But who is to say that once under load, the loco won't draw enough current to burn out more than just an output transistor.
Sorry, but..
paul delany
Registered
Hello thankyou for reply I made a boo boo I applied 12v dc to the motor output terminal on the reciever to test the motors as the pickups were not good on the wheels as a test ,but obviously the circuit design did not take to kindly to seeing 12 v at the motor terminal blockVery possibly, but take a step-back.. Why did the transistor(s) blow?
If there was something that caused the motion to lock, will it happen again??
Every loco that comes my way for work. First-thing, it get's run forwards and backwards on DC, from a bench supply which has current and voltage metering. - This way I can judge how worn the mechanism is. What current it takes (no load) and, if I wish, I can stall the loco (or try to!) and see how much current will be pulled under an extreme fault.
No amount of alternative electronics, will compensate if there is an underlying problem with the mechanism.
You may 'just' have been unlucky, with a sub-standard component? But who is to say that once under load, the loco won't draw enough current to burn out more than just an output transistor.
Sorry, but..
Ah! Oooops!
In which case.. Can you see a blackened / burnt-out component on the Receiver, by any chance?
It might be an output transistor, but could equally well be the transistor controlling the output??
You might only notice a slight swelling in the case, or even just a dulling of the finish to the component?
paul delany
Registered
Yes it smells and there was a bit of smoke I will have to inquire the board and have a closer look,I dont suppose you have any used ex boards lieing aroundAh! Oooops!
In which case.. Can you see a blackened / burnt-out component on the Receiver, by any chance?
It might be an output transistor, but could equally well be the transistor controlling the output??
You might only notice a slight swelling in the case, or even just a dulling of the finish to the component?
Not Revolution, I am afraid..
The damaged component(s) could be under the heatsink? - You may not be able to spot them..
paul delany
Registered
Ok cheersNot Revolution, I am afraid..
The damaged component(s) could be under the heatsink? - You may not be able to spot them..
Greg Elmassian
Guest
The heatsink is removable:
paul delany
Registered
Yes indeed I have removed it and I googled the blown surface mount chip that I blew but couldint find itThe heatsink is removable:
paul delany
Registered
Attachments
Greg Elmassian
Guest
No offense, but shoot one in focus, and we can find the part.
note that one of the numbers will be a date code, not the part number.
note that one of the numbers will be a date code, not the part number.
paul delany
Registered
HI Greg no offence taken i have since got a better picture and found the mosfet on the web yey
Greg Elmassian
Guest
great, let us know how it works out!
paul delany
Registered
Will do greg can I ask what are you modelling these days
Greg Elmassian
Guest
Deep in the throes of getting my diesel fleets with body-mounted centerset Kadee couplers, all close coupled, and adding DCC and 2 to 4 speakers per locomotive for sound systems.
The 11 USAT F3's are done, concentrating on the USAT PA ABBA set now, as the coupler conversion pedestals are being developed... a few more switchers and then off to try to come up with a systematic solution for the slipping drivers (and resulting destruction) on the Aristo-Craft steam locos. Still about 40 decoders to install... but at least I won't run out of things to do ha ha!
Greg
The 11 USAT F3's are done, concentrating on the USAT PA ABBA set now, as the coupler conversion pedestals are being developed... a few more switchers and then off to try to come up with a systematic solution for the slipping drivers (and resulting destruction) on the Aristo-Craft steam locos. Still about 40 decoders to install... but at least I won't run out of things to do ha ha!
Greg