MP chassis sweep coast

[stills]

I have an MP chassis that has the sweep coasting at 66 and home.
The board is brand new zot unit so I know it is not that.
The contactor relays are also new as well as the ice cube relays.
All the connections in the c1 and c2a have been replaced by the gold ones from zot.
I put the chassis on another lane and it does the same coasting.
I have tried other boards and it does the same.
Any ideas?

[rivmike]

Swap or change the sweep contactor (yes new but) maybe a bad one.

[stills]

I swapped out the first sweep contactor when rebuilding to a good proven one.
After it did the same thing I tried a brand new one and still the same.

[Tablejam]

Sounds like either both sets of N.C. contacts have issues (or maybe just one side) or there is a C1 issue. Seems like the braking circuit isn't working maybe. With no power manually operate the contactor several times then do a continuity test across both sets of normally closed contacts, do this a few times, the reading should always be solid and the same. If not then that could be it. Could also be a bad connection between there and the pins in the C1 or perhaps one of the sweep pins got put back into the plug in the wrong spot.

[keeth]

With the MP chassis all sweep activity forward or reverse goes through M2 you can try replacing that ice cube but also look for burnt pins on it as a crappy socket will also ruin your new ice cube. If you have a toasty pin on the ice cube and the socket toasts up a new one after some time you can change just the one connection in the socket as they were nice enough to leave some spares open

[Tablejam]

^Crappy socket...lol

[maister]

If it still does it with a new board, all that is left is the contactor, or a bad contact in the pins under the board, perhaps check they are gripping the board firmly.
Just a thought.
Maister

[Kat]

Just for giggles, ohm out the contact points on the T Contactor as well. Remember there is a shared line between them.

[DarkDays]

I would use a multimeter to check and make sure you are getting 24vac on the relay windings for both the contactor and M2 socket, then check to see if you are getting 120vac aross all the contacts on the contactor. You may just want to replace all the power wires that go to and from the contactor if you can figure out the problem.

[stills]

I will try all this on friday.