QUOTE (cunnini @ 21 May 2008, 19:20)
<{POST_SNAPBACK}>i pretty much know the fault lies with the point - see my O level physics was useful!! i just need to know waht to look for in the point for faults and how to find the fault.
i'm particularly confused as this wasn't a problem a week ago, and has recently occurre, but without any changes to the trackwork/wiring etc.
thx for all the help so far, but please add further things to check etc !!
Hi
OK... heres a few things to think about and check...
If it was working one day and not the next its not wiring unless its related to changes or failure of a component in the point...
such as an spst changeover switch on the frog etc.
Its going to be either a point problem or something silly and small thats just not noticed... if it was OK one day and not the next, its probably the "silly thing".
So... keep first checks simple... its often staring you in the face.
Example: when I was wiring my layout I was also progressively replacing the last couple of sleepers on each board with copperclad. I came into the layout room one day to continue and connected my screamer across the rails and it sprung into life. (The screamer is a piezo buzzer type device I connect across both rails when wiring to warn me I've screwed up and swapped left bus wire to right rail dropper accidentally - I use it as lamps and meters are useless when U are under the board with a soldering iron)
It took me hours and hours to find the problem - and I was really P-ed off when I found it.
I'd a box of copperclad sleepers on the layout and when I cleaned up the night before I'd chucked the spares at the box and one had missed the box and landed face down on the track - so small it wasn't noticed and copper side down so it looked harmless but wasn't... A B**** frustrating problem to say the least on a complex board which had a dozen hand made points including 3 slips and two diamonds on it - which I of course blamed first so I de-wired de-wired the lot!..... making a lot of work when simply clearing stuff off the board would have found and fixed it!
So - first do the obvious:
* make sure no wire other than the two feeds at the toe are connected.
* Take everything off the track and vacuum it all over. if possible separate the toe end lead in track from the layout for the tests so U are just working with a Y shaped bit of track.
* disconnect the controller from the track too (you want nothing else electrical or electronic connected when using a meter to check for shorts)
* check with a meter to reconfirm everything.
* If its still a problem, Look at the gaps between closure rail and frog - has either of them closed up?
* have either of the two gaps at the heel end/frog rails closed up?
* are you switching frog polarity? if so disconnect the switch centre or common wire - does this fix it?
check between the point blades and the closure rail - has a tiny bit of metal, small screw or wire end dropped in there? run a fine screwdriver tip between closure rail and point blade to dislodge the "metal or invisible stand of copper" and then Vaccum the point really carefully just in case.
recheck
if the short is still there and you can't see the problem then separate the point from all other track and repeat the test.
For perfect reality with Peco - use other brands (only joking, sort of...)
DO consider making some mods to the point though.
* totally isolate the frog. from every other rail. for OO modellers the code 75 its almost already done for you - haven't looked at an N scale peco point for years so don't know if it is or not now - if not, get out the dremel..... and cut it.
* solder wire from closure rails to adjacent stock rails (LH closure to LH stock rail) (RH closure to RH stock rail)
* remove those silly tabs if they are there (are they there in N?) - if you do the first two things they aren't needed anyway. They are bl**dy useless things as the layout ages, they always fail one way or another
* solder a fine wire between closure rail and point blade (this linkage fails after ballasting often as the eyelet corrodes and they
become elctrically iffy and sloppy too.
* connect the frog to a changeover device that will change the frog polarity as the point is changed. I prefer to do it with my
own MASTERswitch product but the peco switch will work too.
Richard