Sad Mac 04919A

[captjon320]

Hello all,

I have two 128k boards that I’m working on.

The first will bong on startup with SadMac 04919A.

04 = Memory Test-Mod3 test and identifies a bad chip or chips.

A sub code of 000A sub code meaning is Line 1111 (I don’t understand what that means). Also, I don’t understand the first part of 919 as well.

The second one I’m working on has error code 040010. My understanding of that code is to replace chip in location F9. If my understanding of the second code is incorrect, I would appreciate some guidance.

Any and all help on the first error code is much appreciated as well.

 

[dochilli]

If my interpretation is right 04919A means the following:
9 = G12 + G9
1 = G5
9 = F12 + F9
A = F8 + F6
Hope it helps...
May be it is time to change all RAM chips.

 

[captjon320]

dochilli, thanks for your help!

Yes, I was planning on changing them out as a start.

Always wanting to learn, can you direct me to where these nuggets of information are revealed for future reference?

Thanks again

 

[dochilli]

myoldmac.net - Sad Mac error codes on the original ROMs 128k, 512k, 512ke, Plus

68k Macintosh and Apple F.A.Q. - Supplies answers to common and not-so-common questions about 68k Macintosh and Apple ][ use.

myoldmac.net

Look at the sub code bits. The code is hexadecimal (0..F), so if the sum of one bit is 10 then you get an A and so on.
Perhaps you can use sockets for the new RAM, then it is easier to change them in the future.

 

[captjon320]

Appreciate it, many thanks.

 

[captjon320]

Thanks for all you help. I got both 128ks back up and running. Replaced all the chips (new are socketed) on the multiple failure board and a single one on the other.

Now I have another project with a 040038 sad Mac code.

I believe this to be a bad RAM chip at G7?

If this is incorrect, I would love to have someone correct me. Thanks again for the group knowledge

 

[dochilli]

0038 means that F9, F10 and F8 are defect.