MTH 30-11006 crossing signal connection

Odd since MTH says ac or dc. If you do the diode thing again, put a capacitor (say 470uF at 25 vdc) across the output to store the charge for dc. Should work then.

Thanks Chuck,

I'll give that a try!

S/F Mike

Is it practical to pop out the circuit-board in the signal base?  Based on your experiments I'm thinking a defective capacitor which ought to be easily identified and replaced.  I figure there will be a diode(s) near where the power comes in for the AC-to-DC conversion, and then a electrolytic-type capacitor right next to the diode(s).

Mike Summerville posted:

Thanks Chuck,

I'll give that a try!

S/F Mike

If 9vdc works, you only need to rectify from about 5 to 6 vac

Thanks Stan,

Yes, I think the board would be easy to check, mounted right in the base.  I did not look at it but  my friend has...but he was looking for more wires!   I'll ask him to bring it back over and we can check for a bad cap.

Thanks again for the assist!

S/F Mike

A photo of the guts would be good to have for the record.  If it indeed turns out to be the capacitor, I figure it will happen to someone else...

Best I can do with my phone. 

The big capacitor on the left..,it would be open or disconnected 

Thanks so much all!  Spoke with my friend Charles and it will be Saturday before he can make it back over but I'll be sure to update you all on what we find (now that we know what to look for!)

Thanks again, Mike

John H posted:

Best I can do with my phone. 

Looks like they had to add the caps rather than plan for them when laying out board. Or couldn't find small enough caps to fit so had to jam in bigger parts.

It works obviously, but sure looks "kludgey" and "homemade" (my 2.5 cents opinion).