Rockola 451

I have a Rockola 451-100 that will only play the top side of the record but not the bottom. I can press the 2nd button (which chooses the bottom side) and the "1st digit lite" is illuminated. Pressing any button after that initiates the next part of the selection sequence and the
"2nd digit lite" is illuminated. As soon as I press the third button (which would complete the sequence for that particular record choice), the unit resets and all of the selection lights turn off. I have verified that all componenets on the selection control board are good (SCR's, capacitors, etc.), fuses good, etc. Any ideas out there? Thanks, Walt

Walt,
I really don't know as I don't think that I ever saw that model--but I have a guess or two---
First, look in the service manual for anything "unique" to the B side selections--like maybe a relay ? 2nd, look at the two ("Selection") PCB plugs (going to the board with the selection SCR's on it). If they are the black colored (Amp Brand) type, check all four corners of the plugs looking for "splits". That type plug, in the black color, was defective. If there is a "split", a temporary fix is to use "strapping tape" to hold it together, but you WILL need to replace it--soon. White colored plugs seem to be OK.
You might also email Harold Hagen at http://www.alwaysjukin -If you subscribe to the magazine, he will answer. If you don't subscribe, he MAY answer anyway (IMHO, It's worth the price of a subscription). Ron Rich