Mac 128k unlisted error code

[batwings21]

Happy New year! Looking to start the year out right by finally fixing my 128k Macintosh. I started with a ram error code for the first chip. I replaced that with a socket and a 4164-15 which I think should be compatible. Now I'm getting a code I cannot find anywhere. 04000C

Any ideas? I have tried another chip same part number. I checked my solder connections between the socket and the next chip.

 

[Stephen]

Now I'm getting a code I cannot find anywhere. 04000C

Any ideas? I have tried another chip same part number. I checked my solder connections between the socket and the next chip.

I'm by no means knowledgeable with these error codes, but if I'm reading this guide correctly you have "Zero Divide" error. Maybe a ROM issue (like corrupted ROMs?). If you have another machine maybe you could try swapping ROM? That being said, the line makes me think there's a memory issue persisting but again, I am not an expert!

 

[batwings21]

Actually, I just fixed this. It was two more RAM chips, bit 3 and 4 which added together in binary is 1100 or 000C in hex. I changed chip 3 following a hunch and was left with 040008 which showed chip 4 as bad. Now with 1,3,4 all socketed and replaced it is now asking for a boot disk.

 

[Stephen]

Actually, I just fixed this. It was two more RAM chips, bit 3 and 4 which added together in binary is 1100 or 000C in hex. I changed chip 3 following a hunch and was left with 040008 which showed chip 4 as bad. Now with 1,3,4 all socketed and replaced it is now asking for a boot disk.

Awesome! As a matter of curiosity, where did your source your replacement chips (and what chip are you using)?

 

[batwings21]

I bought some 4164-15's and sockets from Jameco for about 1.25 USD each about two years ago for my Apple IIe repair.

 

[The MAC MANIAC!]

I have had many issues with memory. Once I got a Plus computer off eBay with weird lines going down the screen. I knew the machine worked because the floppy icon was visible. I assumed it was the Analog board had leaking caps. So when i replaced them I tried just about everything even cleaning. Later when i got another one I swapped parts back and forth only to find out one of the memory sticks were bad. So its not surprising  this is an issue in the future because they fail all the time especially if the pins are corroded.  The new one I have is pretty much mint