Macintosh 128k: Logic board, which revision?

[Paolo1960]

Hi

This is mybsecon post, and my first thread, in this fanatstic forum.
I read several discussions to repair my 800ks (or try to repair my mac Plus- still on going)

By the way, I have recently bought on ebay a 128k for more or less 400usd (I live in Europe). Once arrived I opened it to see what was the cpu used and other little things. Unfortunatelly it was not the one that most people define "the 128k logic board" (+ a lot of rust)

So now the question: has the following board been upgraded? Is there anything in this board that can be considered "original 128k?





Thanks a lot for the feedback,
Paolo


Ps: it powers on but the sound is totally absent.
If you have any idea on what could be the issue It would be great

 

[bibilit]

As far as i can see, this is the first revision of boards.
Following units had a label for either 128 or 512k ram.
Yours is 128, and ram is original, don’t see any work done to it.

 

[Paolo1960]

As far as i can see, this is the first revision of boards.
Following units had a label for either 128 or 512k ram.
Yours is 128, and ram is original, don’t see any work done to it.

I said upgraded, or reworked because the James'one shoulb be the first release: Link
In the one I have Ram slots do not have the apple logo on the left side, but on the right. Cpu is missing the "Apple 83 etc etc" thing, and is also called HD6800.
Maybe there were some revisions before the dual logic board (128k/512k)
Thanks,
Paolo

 

[cheesestraws]

Different manufacturer for the ICs, is all. Note that several on your board are manufactured by Oki, including the DRAMs. Consistency implies they're probably original.

I'd guess manufactured in a different region?

The board is a first-iteration 128k board.

 

[bibilit]

Rust is probably related with battery juste above the LB, nothing a good scrub cannot get remove.

 

[Paolo1960]

Rust is probably related with battery juste above the LB, nothing a good scrub cannot get remove.

I will use isopropyl alcohol (99) to clean all the board. As far as I know It should be safe.

Different manufacturer for the ICs, is all. Note that several on your board are manufactured by Oki, including the DRAMs. Consistency implies they're probably original.

I'd guess manufactured in a different region?

The board is a first-iteration 128k board.

The manufactur theory is intersting. I will try to analyse other 128k boards
Thanks

 

[Paolo1960]

So, I disassembled my other Macs and this is what I found:

128k - Dual Logic Board


512k - Dual Logic Board


All of them are different, but The position of the components is always the same.

Concerning the sound issue, is there any suggestion on what to check?

Sorry for the consecutive posts,
Paolo

 

[bibilit]

Bad speaker ?