possible fault

hi all

i have a possible problem with my cdu.i have recently been fitting points motors around the station area and checked each one as they were fitted.all was ok.i then ballasted the whole layout.now the motors don't work.i don't think that the ballasting is the problem,i.e shorting because the motors work from the 16v ac outlet from the gaugemaster d. all outlets from the controller have been checked and are ok.is it possible for the cdu to have "just failed".

That's a difficult one, Alan.

If everything worked before ballasting then that must be the prime suspect.
Worth checking again - even to tearing some up at sensitive places.
Maybe a wire become dislodged.

Of course, any unit can fail but most likely there is a physical outside cause.
Can the unit be tested off layout?

Ron or someone will know.

Alan, I presume you have tested the input using the multimeter on AC volts -16 or there abouts?
Then checked the output - 20 + volts DC?

No output - then disconnect the wire going to the switches - that is remove the motors, etc  from the CDU, re-test output.

No voltage- then CDU is slightly stuffed & it is possible to repair but sometimes cheaper to buy a new one.
Gaugemaster sell one.
If there is now voltage, it means that you have a short in the wiring - a slow progresion is required to find it.

DD.will bypass cdu tomorrow.don't think it's the ballasting,different power source.

Ron.17v reading on multimeter at controller.nothing at cdu output to motors.sort of answers my own question.will bypass tomorrow to confirm.if it is the cdu,strange .works one minute and not the next.

[user=1033]spurno[/user] wrote:

…………………………………..if it is the cdu,strange .works one minute and not the next.

I'd guess that's the way it goes with electronics.  You can't see them "wearing out".  A bit like a light bulb ………:roll::roll:

hi Peter
it's almost brand new,hardly used.suppose that's what you get for buying off ebay.

Alan, to test output voltage, make sure all wires to switches, etc are disconnected.

Electronic components are known to stop working at at moments notice & that includes new items ( as they are not all manually tested before sale)

hi everyone. all seems to be working now.i'm still confused though.measured output at controller,one minute nothing then 17.3 volts.bypassed cdu,nothing then reconnected and everything worked.i also checked track power while i was at it and that's all ok.it might be an intermittant fault on the 16v output,i will keep an eye on it.
thanks to everyone for their thoughts.

Alan, if you are feeding 16vAC in, the output should be higher than 17.3 - more likely nearer if not over 20v.
But good to read that it works for you now.

CDU and related info

CDU - an Overview

Electronics are female - they have a mind of their own!