Most of the day was spent trying to get another working MCU for the SMC2. I have several with only one working. It is out of the SMC2 Hideaway unit and is sacrosanct. It is my test mule and will eventually go back into the Hideaway when its turn comes for restoration.
Testing the boards on these requires a lot of patience and the ability to remember what was done with what. Mostly because these can only be tested fully assembled in a case and connected to the juke. So each change requires removing the boards from the case, dis-assembling them, changing out whatever is decided to be tested next then re-assembling. I cheated a little bit by holding the MCU in hand instead of mounting it and turning the jukebox on with the other hand while observing.
The first thing I did was test all the 40 pin CPU chips out of four main boards in the Mule. They were all good to my relief. They can have extremely fragile pins and I take extreme care when pulling and inserting them. These are the main processor chips that the mask was lost and cannot be replaced. If nothing else I have 4 good programmed processors. On one of the boards I got the idea that the P5101 RAMs were bad and replaced those with new ones sourced through ebay. Almost all the chips used in these are “obsolete” and ebay is a very good source. Two new RAMs didn’t fix it. To make a long story short none of the four main boards would work. One of the boards had several solder cracks around many pins and one of the factory jumper wires was broken. I found so much wrong on this one that I had high hopes for it working. Alas, it did not.
I find this sort of stuff interesting so you, dear reader, will just have to suffer through. The bad boards when assembled with known good display and pricing boards exhibited differing behavior. One was just dead. Perhaps a voltage regulator issue. Another would not scan for initialization. The last two would not stop scanning. Perhaps their issue has to do with recogizing either the detent pulses or the limit switches. One day I will break these out again and try to repair them.
I will have to get one of the Gen 2 boards for the SMC2. I think they’re a bit high-priced but what ya gonna do? We are lucky to have them available. Ron Rich had me fooled. I thought he was the source of these Gen 2 MCUs and when he passed away I thought “That was it. No more Gen2s. No more SMC restos.” After some searching I found out that Ed Fischer of Data Sync Engineering actually makes these among several other pretty neat jukebox stuff. I called him and we had a good long talk. He is an engineer extraordinaire. I actually understood most of his technical explanations which I think he appreciates and look forward to chatting with him again. And, to make it clear to get the word out. These GEN2 boards are available through their commercial site https://cdadapter.com/
My Seeburg Life 