Wallbox 507 on a 474 no longer working

[c5z]

Greetings All,

This looks like a great place for some advice.

I have a 474 that works fine selecting and playing records when done at the main unit.  My 507 has stopped working several months ago and I did some troubleshooting and this is what I have found so far.

When a valid selection is made on the wallbox, the 1769 receiver unit does receive a train of two sets of pulses to the LETTER coil according to the manual and advances the stepper, the NUMBER coil does not energize at all. 

Sometimes the record table will spin a complete cycle then stop between 100-197 as normal, sometimes is just jumps a little, sometimes nothing.

NO reaction from the pinbank mech.

Did a quick clean of contacts on the receiver unit.

I while back I do remember that one time while using the wallbox, it played several wrong songs to the selections that I made.

Hopefully someone may have some insight to this problem.

Thanks in advance,

Kevin

[Ron Rich]

Hi Kevin,
From what you have written, it appears to me that the stepper is not transferring from one set of pulses to the next ? This could be a failure of a timing cap, or a failure of a contact set. See our FAQ;s section on how to clean , care for, contacts. It could also be a failure on the wallbox side--have you lubricated that wallbox lately--it could be "slow" ! Ron Rich

[c5z]

Ron,
Thanks for the reply. I pulled the wallbox apart and cleaned the contacts associated with the stepper motor, it does not act sluggish, problem still continues. I found in the receiver manual about one cap(50MFD) that is used in the circuit and located it underneath. Actually, it's a 47MFD 75VDC and I have an exact replacement on order.
Kevin