AMI Rowe R-81 only plays A-side selections

Just sold my last R-81 which was working perfectly the last time I fired it up about three weeks ago. It spent a few weeks in storage before I moved it to it's new home today. When I plugged it in and tested the machine, everything worked perfectly until I tried to make a B-side selection. The correct song displayed on the selection area and the correct 45 was chosen. However, the Toggle Shift light did not illuminate on the Mech control unit and the solenoid did not engage. I have spare mech control and memory units and swapped out each, one at a time, with the same results. The manual indicates that if the B-side does not play and the Toggle Shift light does not come on that the memory control unity needs to be replaced. However, before I invest in a new one, I want to make sure that this is truly the issue, given that everything was working just fine a few weeks ago prior to this recent move. I checked all connections and found no loose wires or obviously wire breaks.

Also, there is a two-pin connector port at the bottom of the mech control unit. I dont remember anything being plugged into this port on any of my R-81's (I have rebuilt 3 now) but wanted to make sure that I am not missing something there. I could not find any indication of what this port is for in the manual.

Any suggestions on troubleshooting would be GREATLY appreciated.

Thanks,

Dane

Hi Dane,
If you have replaced the memory control unit and the mech control unit, I would suspect the wire(s) supplying the toggle pulse, are not making good contact. Didja remove/inspect/"re-form" the individual pins, in all plugs involved ?
When you "rebuilt" that phono, did you re-flow all solder joints that could be involved ? Ron Rich

Ron, thanks for the reply. Reflowing solder joints today in case there is an issue there. Also plan to pull another solenoid to confirm that the one in place is not faulty. Will report back as soon as these steps have been completed.

Was able to take a look at the memory units today. One has a note "bad LSI chip" in sharpie on the back of the metal plate. Both also had a 3-pin connector with two wires that went nowhere (see photos below). Any idea what this connector is for and why these wires would be dead ended?





I re-flowed solder to the connector pins and swapped out the 23uf 25v caps on the one board without the bad chip note.

I also have a replacement solenoid on the way in case that is the issue.

It appears to me ( not sure ?), that there is a battery symbol to the right of the plug in the last photo--and I see a "+", and a"-". If that's correct, I would assume a battery should outta be connected there ? Ron Rich

Those wires went to a 3.6 volt nicad battery pack. It's not really needed for a home use machine.

Hi Ken,
That was my guess--However, due to the nature of some, LSI, and other "power required for memory", chips, they can be very "fussy", when denied their 3.6 volt supply, especially as they age ?? . Ron Rich

Hi Ken,

I agree with Ron that the memory units should have the 3 x 1.2 volt rechargable cells fitted.

One of the things that always gets me on the batteries is why Rowe Ami got the cable colours wrong on the battery connector, I like to see a black wire going to ground not a red or red/white.

Regards
Alan

Alan Hood
ami-man
UK

Hi Alan,
"Rowe engineering" liked to be "unique" in many respects--reversing such things as common wire colors and audio outputs, went right along with using caps that were marked with "arrows" pointing to the + end ! ( Yes--I screwed up once in not realizing the arrow pointed to that plus side-- ) Ron Rich

Hi Ron,

I guess they were a bit like Seeburg in that respect, using positive can capacitors got people into trouble in a number of countries where these were not avaiable, it did however improve the rate of insulation tape sales

Regards
Alan

Alan Hood
ami-man
UK

Hi Alan,
These were not "cans"--they were PCB mounted caps---small values--
Seeburg tended to mount all CAN caps, on insulators, both pos and neg "earthed" ( grounded) units.
Ron Rich