Broken pins on MK3870/20

Hi all. There seems to be a wealth of great info on here. As luck would have it I still need to ask my question(s).

My father just picked up a seeburg SMC2, when we powered it up it didn't really do much except light up.
I got a bunch of digits across the display, mostly 8's and a couple backward L's if I recall. Anyway, fast-forward to cleaning up the MCU3. I can see that the 3 electrolytic caps on the (CPU assembly near battery connector) appear to have residue on the outside, so I plan to change them out. (in truth it could be corrosion from batteries, as there has been significant leakage in the past, to the point 2 battery holders no longer have clips)
Two of the caps are rated at 4.7uf and one at 47uf. Someone else has already made repairs to this unit as the battery connector was removed and the wires soldered to the board and silicone applied. I want to be sure before I change these 3 that the ratings are correct and that someone didn't mistake a 4.7 as 47 and attempt a repair with the wrong value.
I can't find a schematic anywhere on this.

Next while cleaning I removed the MK3870 to find that one pin was broken and stuck in the socket still.
I read a post where Mr Gorf soldered a header pin set to the chip. While this is an option, I'd rather not introduce unnecessary heat into the chip. I can't find Mostek 3870 chips online, but I'm reading where it is essentially a fairchild F8.
Can anyone confirm that if I were to purchase an F8, that it would perform exactly the same?

Lastly do any of you have any IC's for sale? (Just exploring my options)

Thank you all in advance

All's I can say is "rotza ruck!" The Seeburg dump version of that chip has been NLA for at least thirty years--Mostly because the Mostek brand chip pins broke as, you state.
Also some of the display drivers are endangered species--
For that reason, I and a couple of other guys designed a total replacement for the boards in the MCU--I have been building it for over 5 years now--only one was returned, because it "did not work"-- After examination, I questioned the person further, but he declined to admit anything other then he "probably did something wrong", and offered to pay the repair charge. PM me if you wish to purchase the Gen 2 MCU. Ron Rich

thanks for the quick reply.

Just to clarify if anyone was wondering, I looked at the solder joints on the 3 caps in question. Based on the shoddy work the previous person did, I think I can safely assume that the values for the caps in question are the ones from the factory. The joints look too clean and nothing like the pigeon poo piles they made on the credit board jumpers.

Hi Patrick,
Do you know which MCU is installed in that phono--Seeburg/Stern-Seeburg/ Seeburg Phono corp/ Seeburg international ?
I would assume that to be true--BUT, why don't you purchase a copy of the Technical Manual, to be sure? There are several copies for sale on ePay at the moment--If you have any other then the Seeburg version, there will be a number of "re-design" differences, The Stern version was the last one to provide a schematic, as far as I know, but it was not included into the manual--just supplied with each phono, on a separate LARGE sheet, which you may need to purchase from one of the book suppliers listed above. Ron Rich

There may be something in the bottom of the machine. I only ran across a blue soft cover booklet labeled Seeburg SMC2 Installation and Operation.

The outer casing of the MCU has a label that says MCU3.
The CPU Assembly has Stern 1980, silk screened on the board.

If I don't find any other paperwork in the jukebox I'll strongly consider as you suggest.

Thanks for the suggestion of ordering the books.
I ordered from vintage glass. I'M at a total loss. So much great info, clean complete reprinted manuals. Not even as though they have been copied from a failing copy. Very legible, very nearly as if from the factory.
It is surely to make getting this machine back in it's former glory much easier.

Just browsing through the books at work, and I can'tell wait to get home and start breathing some life into this beast.

Maybe i'm feeling a little sick...

After much poking around it looks like this machine was never prepped for moving. Hopefully this does not mean that the player assembly is beyond repair.
I see a lot of comments suggesting if it was never locked down for shipping you may as well trash it.

Hi Patrick,
Unless that phono mechanism was parked dead center, and the cabinet "bounced" on it's back, you are probably safe in that the SMC models are least likely to suffer catastrophic damage when not properly bolted for transport. As long as the base casting is not bent ( did see one SMC that was bent), it's salvageable. Ron Rich

First power up after cleaning and reconnecting all (previously unknown) battery connections.



Tried credit switch, and changed position from normal play to audit, and popular. Didn't seem to have an effect. I wasn't sure if I needed to power the unit off for changes to take effect. After about 3-4 power cycles it displayed like this


Any thoughts? Do you think this connected to the original issue of the broken pins?
I only recapped the electrolytic caps, none of the ceramic.
On the chassis I saw 2 of what I thought from my previous experience were diodes, but after looking at the schematic and Ron explained they are not. I've never seen glass caps before.
Should I be recapping everything?
I was never aware that ceramic caps needed replacing since they do not leak.

Thanks,
Patrick

Patrick,
That ain't caps-- that's (a) failure(s) within the MCU--the main reason we developed the Gen 2 MCU. IMHO, you are wasting your time attempting to repair that unit---they are prone to interment's such as you are seeing. Ron Rich

Ok. Much appreciated.

I think it's safe to put this thread to rest. I'll be in contact via PM when things look right to order a Gen2.