Mac 128k logic board

[beachycove]

I have recently agreed to buy what is effectively a new in the box Mac 128k, which boots to what I believe may be a memory error (Error number 04038C).

Question: Would the simplest way to repair be (a) to replace the chip with a socketed chip; or ( B) to find a replacement logic board? How common is either of the two items?

 

[beachycove]

OK, further to this, there has been a change of plan. The gentleman wanted to break the lot by keeping the boxed accessories/ manuals and to sell the non-functional 128k only, without keyboard or mouse. I reckoned this was a kind of sin, and was financially a bad, bad idea, so we agreed together to see about getting the machine going with parts from another 128k. Thus out of two machines, a pristine, boxed 128k will be preserved. Alas, it will not be mine. However, the trade-off is that I will get the doner machine for a small sum and the logic board from the non-working unit.

I did, however, have a good look at the machine in question and it is truly just like the day of manufacture (except that it no longer works!). There were still tiny pieces of styrofoam in the top vent holes. Wow.

All of this means, though, that one of these days, I am likely going to have this error message and the problem of a machine that does not get so far as to spin up a floppy drive....

I propose:

1. reseat ROMs and see if that does the trick;

2. have a guess at the problem from the number - it seems to be a memory error;

3. get replacement RAM chip from somewhere, someday, and put it over each of the RAM chips in sequence to identify the problem with more precision;

4. desolder the old and resolder the new.

5. Failing that, a new logic board.

Have I missed anything?

 

[Mac128]

This is almost certainly bit rot. I would be interested in the serial number on this pristine Mac, whether the bad board in question has the notorious Apple-branded RAM chips, and the story behind how this new-in-box 128K came to be 25 years later.

 

[beachycove]

i have no direct access to the machine (fool that I am, I turned it down for $60 and told him that he needed to keep the package together), so I can't provide many details. However, I am told that the manuals are in Arabic and that it had come here (Canada) from Saudi Arabia. The model number is M0001P, which is apparently a non-North American designation. The rear has a very small mailing label sticker near the power socket saying 110v, which I may mean that the ps was changed at some point along life's way, but who knows?

It looks to me like the thing might have been purchased by someone with lots of money (Saudi national or someone in the oil industry?) as a toy, used for a few weeks and then put away. But that is just speculation, and as I say, I have no access to it at present. But I am hopefully going to be present when the replacement board is installed, so at that point I will be having a darned good look.