Seeburg SMC 2 selection problem

I have a seeburg smc2 that has a selection problem. The problem is on coin and select freeplay, the buttons pushed do not register the correct numbers. Sometimes it will scan and pick up a record( not the correct one) and sometimes it won't pick up a record. If you put it on continuous free play it will trip at each record, play both sides and then move to the next with no trouble. Any ideas what the problem could be or troubleshooting tips to try?

Does the "selection being made" display agree with the buttons pushed ? Ron Rich

No. Say for instance you push 255, the display reads like 022, or 211. It does this both on coin and select free play. In service mode, you push 99 or 00 for free play modes and it registers fine.

You have an internal problem in the MCU--If you wish to troubleshoot it, I would advise that you purchase a copy of (the late) Tony Millers "Red Box and MCU" book.
If you wish to hire me to repair it--Please contact me off list at ronnnrich@yahoo.com Ron Rich

My friend has a 1979 Seeburg Prelude with the SMC 2. It used to work before he got a divorce, and we think his Ex Wife stole a cord out of it. Does anyone have a wiring diagram for it?
Thanks

Wiring diagrams are available with the Service Manual package. See above, "announcement" "books---where to find". Your description of what you have is confusing. Seeburg made the SMC-1 Disco for the year model 1979, The SMC-2 Phoenix as an 80--but only a very few (maybe only one ?) were made. Stern/Seeburg made the SMC-2 in 1981, and Seeburg International made the SMC-3 Prelude in 1984--
If you can describe where this "harness" goes, or shoot a photo, I MAY have it--
I do have brand new re-designed, MCU's for all SMC, and 100-79M models for sale--
Ron Rich

Thanks Ron, I will try to get some pictures soon.
Jeff