Skip to main content
Home Forums Mac 128k ~ Plus Analog Board Analysis Mac 128k ~ Plus Analog Board Analysis
Thread

Mac 128k ~ Plus Analog Board Analysis

Mac 128k ~ Plus Analog Board Analysis Troubleshooting 44 posts Jun 30, 2007 — May 15, 2010
Interesting "post" indeed, shred!

There was a book used to identify parts - usually from photos, with notes guiding you as to subtle differences between boards (i.e. if the IC at position X carries part number yyy-zzz, then it's board A, otherwise board B and so on)
You wouldn't happen to own a copy of that book, or have copies of the pages in question, would you?

The late model boards with the white polyester capacitor at the top appeared in the very last run of Mac Plus computers sold in Australia.
You are talking of C1.

Here is a photo of C1 in a later edition Mac Plus analog board.

Here is a photo of C1 in a stock Mac 128k analog board.

Today i got another Macintosh Plus. It's from ©1988, with analog board version 630-0103H (630-6140) - there are two stickers with numbers...

here are some photos

You wouldn't happen to own a copy of that book, or have copies of the pages in question, would you?
No, sorry. It took the form of a large ring binder book. Every month an "update" would arrive with instructions to remove this page, insert that page from the update and so on. As such, it was always up to date, but you only ever got the one copy of it.

I think I have some old parts price lists somewhere. They take the form of HyperCard stacks.

I probably should point out that Apple always referred to the "analog board" in the 128 / 512 / Plus as the "Power / Sweep Board".

shred, I would love to see those stacks.

chinchilla-99/szynszyl_99, I found your photo interesting. But unless shred has evidence to the contrary, I am going to assume that the "3" in your analog board's part number sticker pertains to international boards only, as opposed to a newer edition of the 630-0102 US boards. The latest edition US board I've seen, based on the handwritten letter following the part number, are marked "E." Here is my photo of an "E" board.

Hello all,

I found two mac boards at my high school about nine years ago and I had no idea what they were. I found this forum and topic about 2 years ago, took detailed pictures of the boards and was going to post them to find out what type of mac they went to or what revision they might be. As fate had it I times got hard and I lost my net connection etc...

Well I'm back and here is a link to my flicker page http://www.flickr.com/photos/nexarian/.

I think one of the boards revision code is (630-0525-D), the other one im not sure of.

I'm hoping that I'm not too late and that someone can help me identify these boards. I would really appreciate any help anyone can give me :)

Thanks

Nexarian

I think one of the boards revision code is (630-0525-D), the other one im not sure of.
The 630-0525 is a Macintosh Classic II analogue board. The other board is most likely a Mac Plus logic board. The model/rev numbers on are on there. This article tells you where to find them.

Cool, thanks for the quick response.

Yeah, the 630-0525 I figured out- tho i wasn't sure which mac it was for, but I cant tell what revision the 630-0102 board is, what do you think it looks like?
3885858481_079a47fcfb_b.jpg.e793e126ca8134dbdd9eefe11a3d8d72.jpg


Thanks again.

That would be a 128k/512k/512ke/Plus analog board.

Take the vinyl covering off the back and get your 820-number. Your flyback transformer is the very latest SE type so this board was likely repaired as the copyright date is that of an earlier model board, early 512Ke or beige Plus at the latest. Not even sure a 512Ke came with anything less than the 1986 copyright board.

Gaaahhh! Part numbers! In any big company everything has a part number, and that number may be on the part someplace. There is a number for the board artwork, that is the layout of the traces. There is a number for the silk screen legends. There is a number for the bare board. There is a number for the board stuffed with components. There is a functional number, ie power / sweep for 128K, different from power / sweep for Plus. There is usually a bar code to identify the part for warehousing, and of course a part number for the bar code label itself, which may also be on the label. Every one of these items requires a complete spec sheet, which is why engineers go crazy trying to crank out all the paper work. Each spec sheet has its own part number, too!

So every time somebody changes a capacitor spec, the assembled board spec has to be rev'd, the bill of materials for every higher assembly in which the board is used has to be rev'd, the spec sheets for the bar code labels have to be rev'd... it's a wonder anything at all gets done. At I*M it took 3 days to revise the spec sheet for a bar code sticker because the format of a specification was so complex and precise (and undocumented). All to change one part on an assembly and bump it from rev c to rev d.

As a result, there's great pressure to use parts already in the company's system. There may be a new better part available, but you know it'll take you two weeks of paperwork to request the part, and it'll take purchasing 3 months to qualify and approve the part. Not that they do any actual tests mind you, they request statistical failure data, reliability guestimates, costs, production levels, production ramp rates, etc. etc. And if a competitor takes a purchasing manager out to a very nice lunch, you may be asked to redo everything for the competing part. xx(

H3NRY, thank you for the delightful insight to the process. That certainly explains a lot. Especially why it may have theoretically taken Apple so long to revise the under-powered components on analogue board, cost aside. I never stopped to consider the bureaucracy behind part numbers.

Apple occasionally thinks different. The design of the Apple 1 and II, and the Mac were done in the absence of a bureaucracy. (See Andy Hertzfeld's wonderful stories at http://folklore.org/index.py). As a result of designing under the pirate flag, when the Apple II and the Mac first shipped, Apple did not have schematics or documentation. The recent auction of the Apple II rev 1 to rev 2 motherboard documented the company's effort to trace an accurate schematic for the Apple II. There was a "schematic" of the Mac 128 which Burrell did which consisted of separate drawings of each chip and the signal names which appeared on each pin, but it was rather like having a photo of every bolt and piston ring and gasket of a car, without a picture of how they fit together. As a result, for several years after 1984, Apple's engineers had the Beck-Tech schematics in their cubicles, because there was no Apple equivalent.

Also as Andy's Folklore tells, the Mac team broke up after the Fat Mac design, everyone moving on to new projects inside and outside the company, so the Mac was hanging in limbo for a while as "the Navy" picked up the pieces where "the Pirates" left off. This sort of story makes Apple such a fascinating study. Since the return of Steve, Apple has learned to keep a team together beyond rev 1.0, listen to customer reaction, and get 2nd and 3rd generation products out that are ever more irresistible.

Hello everybody

I'm new in this forum ; I own an original Mac 128 (week 24 of 1984) ; it was incidently found aside a dustbin 15 years ago ; althougt the case has yellowed a bit, the inside looks pretty.

It seems that the analog board is failing, because strictly nothing happens at power on. Having a background in electronics, I have checked the PCB ; the fuze is OK, the power switch as well. As far as I could check without unsoldering components, no obvious failure can be detected. No component gives evidence of ageing. I have searched the on the net : no schematics of analog board available. Where do you think I could find one ? It is likely that an amateur has re drawn it, if original does not exist...

Moreover, reparing that kind of switching power is tricky ; has anybody got an experience in that way ?

My PCB is an international one (630-0108) ; thanks to the pictures posted hereover, I have verified that even if the general layout is similar, component numbering is not the same as for (630-0102) : for example R9 and R16 become R12 and R19 in 0108.

Thanks for your help

mp.ls