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pin jumping fault maybe sussed

Posted: Mon Nov 08, 2010 10:28 pm
by DEREK
ami 1100 mech for a while now i'v been plagued with the old jumping pins fault.
swapped search unit and stopping switch unit for some i know are working this never fixed the fault
so it must be on the mech checked all cam switches no problem there disconnected all the diodes (wat a twat that was)
anyway they metred ok' ha realy grasping at straws now started to meter the wiring from the stop switch wipers etc
checking the wiring for the mech reylay (whitch i had changed for a working one) you'll never believe it one of the wires that works its way
from the mech reylay coil up to the small brass plate under the tone arm adjusting screw gave no reading from the tone arm to the relay
the brass screw was actually touching the brass plate but giving no contact not even when a bit of pressure was put on the tone arm
i removed the screw there looked nothing wrong with it to the naked eye anyway re ground the bottom of it re fitted it now it makes
perfect contact (very strange) the thing now is i'v not hat time to check the mech in the cabinet yet (TI 2) but just have a feeling this could
be the problem. just one thing i can't find any mention of that little brass plate or what it's for in my manual (hope someone can explain what it is for ? )

Re: pin jumping fault maybe sussed

Posted: Tue Nov 09, 2010 3:44 am
by Ron Rich
Derek,
If I am guessing right, what you are talking about is the "no record reject" detection screw. That screw should contact the plate if the gripper arm does not place a record onto the turntable. Contact between the screw and plate is the same (electrically), as the magnetic end of record switch. This is not connected with the "stopping switch" problems you are having--UNLESS--both are missing the common "ground". Ron Rich

Re: pin jumping fault maybe sussed

Posted: Tue Nov 09, 2010 11:17 pm
by DEREK
thanks for adding that bit ron i wont get chance to try the mech out till the weekend but i will let everyone know what happens.

ami pin jumping not sussed

Posted: Sat Nov 13, 2010 8:07 pm
by DEREK
been troubled for a while now with this pin jumping lark. in the past i have explained what i'v done but one thing i failed to mention
the 1100 mech i am trying to get going is out of an hideaway unit i keep trying it out in my TI 2 cabinet (just swapping the mech over)
but what i have noticed is not all 1100 mech's are the same, the hideaway mech has more more wires in the 9 pin red plastic socket
one of these extra wires goes from pin 9 to the outer wiper on the stop switch mechanism the plug that is in the cabinet
does not have a wire to connect up to it. anyone any ideas ? thank's derek

Re: pin jumping fault maybe sussed

Posted: Thu Nov 18, 2010 6:51 pm
by ami-man
Hello Derek,

On your 1100 mech is there a double row of cam switches? if that is the case sometimes the extra two cables on the molex can give problems.
Let me know and I will check out the difference in the wiring looms.

Regards
Alan Hood
ami-man
UK