The over heating problem on the SMC2 has been narrowed down to the PCC board. I swapped in a different one and an hour later the mech was still picking up a record when moving from right to left. This has been the defining test. As long as it will do that everything is fine. I spent about 30 minutes with the schematic identifying circuits that could possibly be at fault then another half hour ordering parts from Mouser Electronics. I basically ordered all the IC chips on the board times three with plenty of IC solder tail sockets plus a few tantulum capacitors and the 2N6348 triacs used in these. Just in case any other PCC board needs attention. Always replace both triacs at the same time. These IC chips were dirt cheap back in the day and still dirt cheap all less than a dollar each. There are two iterations of this PCC board. The one I’m working on is the second generation. This evening I removed U1, U6, and U10 and socketed the same. When my order arrives I’ll pop in the chips and see if I deduced correctly. On a board like this, with components as cheap as they are, it is a valid process to just “shotgun” it-or replacing all the chips at one go. I’m trying to be a little more accurate. I might learn something. The circuits affected by the chips I pulled have to do with reading the 100 side of the limit switches and also playing the B side. These are the two biggest faults shown when it overheats.

I worked on the SMC1 mechanism for about an hour and a half. The first place I start on any mech is to take it off the track and inspect and lubricate the bottom wheel and the two carriage guide roller wheels. I’ve found them brinnelled before which means the round steel wheels develop flat spots. Then the wheels slide instead of rolling. This is a result of dirty tracks caused by over oiling that attracts dirt which becomes wheel chocks. The gear tracks are two halves. I roll the mech over one half, take the screws out of the other half, and gently pry it up and off. The cable guide at front will need to be unfastened.

I found a fairly rare problem with the brake cam on this mech. I’ve only seen it once before. A more common problem are the springs on the followers breaking. The followers are no fun to change out because they are so small which makes it tough to set the spring tension and hold it in place to tighten down. One almost needs three hands. Anyway, it looks like the metal stop for one of the followers wore down. This will give a half-hearted swipe of the cartridge brush cleaner. I’ve found a few hinky things on the Stern version of the SMC that don’t have quite the quality of a Seeburg made Seeburg. My fun started when I tried to install a replacement brake cam. The roll pin went about half-way and wouldn’t go any further. I hit it as hard as I dared which then made it a booger bear to get out. I promptly shattered my 1/16 punch trying to knock the roll pin back out. A 1/8 punch is just a little too big. I did eventually get the roll pin back out. I then bevelled both ends of another roll pin, cleaned out the brake cam and camshaft holes with a file. All work I should have done the first time. I took a quick look hoping that I hadn’t bent the camshaft. They’re not difficult to replace, just tedious. This time everything went together like it should with the roll pin fully set.

The top motor mount on the NiDec three wire motor was ruined. It got oil soaked which softens and deteriorates rubber then almost fully dried out from years in storage. I don’t have any NiDec mounts but plenty of Bodine mounts. They’re different, the Nidec motor mount inside diameter is much smaller than a Bodine. I bought a few cool adapters from Victory Glass. They’re basically a metal ring that fits on the NiDec motor taking up enough space to install the slightly larger Bodine motor mount. The ring went on the motor well with a good interference fit but its outer diameter was a tad small. The Bodine mount was too loose. I did what any good man would do-I broke out the JB Weld and after cleaning the inside steel very well epoxied the two parts together. I’ll leave it overnight and see what I have in the morning.

There has been a development on the SMC2, finally. What with replugging the mech plugs onto the PCC and seeing it work correctly I popped all the pins out one at a time today on the mechanism plug and soldered the wires to the connectors in case of a loose crimp. The jukebox worked perfectly for about 30 minutes and then back to its old tricks. Hmmm….. I turned the jukebox off and an hour and a half later turned it on and it worked perfectly….for about 30-40 minutes. Something is heating up. Interestingly Ed Fischer, the inventor of the Gen2, called last night and among other things asked how the Gen2 was doing. I related the problems I’m having among others the fact it won’t do its built-in tests and the fact that after subbing in the repaired harness the Gen2 picked up the 100 selection it had been looking for but couldn’t “see”. And as posted before, once I selected 100 again the mech just scanned. I ordered another Gen2 for the SMC1 coming up. This is when I will find out if the first Gen2 is actually bad or not. For the time being, knowing that something is overheating I will test only with the Seeburg MCU. It has been rock solid. The boards look new. It came out of a very rare SMC2 Hideaway Unit.

The turntable looked terrible on the SMC1 mech. Most of the paint was missing. This turntable is painted flat black and has six chrome circles embedded throwing a little sparkle that is relected off of a chromed “mirror” as it rotates when playing a record. I can see where Seeburg got the idea for a disco ball for the SMC2. Aside from 1978 being the Disco Era anyway. I took the turntable off and was so glad that it basically slipped off. Most of them are difficult to remove and require some very careful “persuasion”. I popped the few circles still on it off and then sandblasted it. I rubbed it down with steel wool, cleaned it with a water based cleaner, taped off the center spindle hole and painted it several coats of flat black. I did this with it laying on its back so it remained unpainted just like original. It came out very nice and will look good as new once the chrome circles are epoxied back on. I love having a sandblaster to use for repainting parts. Paint will always show anything underneath including old paint pock marks and whatever cracks there are, missing spots, etc. Once sandblasted down to bare metal I have an absolutely smooth clean surface to start with just like the factory.

I tested Kevin C’s black and gray boxes and found no problems. When I initially tear these down I look of course for physical damage but will also reflow solder cracks almost always found around the long board interconnect pins and clean the edge connectors. These actions may well have fixed any problems. The boards will get recased and I will only charge a small checkout fee per box. They will be in the mail back to him tomorrow.