68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.
Mac Classic Error Code Help
Posted by: pj931 on 2020-04-27 13:40:58
Hi,

I posted a bit ago with some CRT issues and 5v/12v issues. Another Mac has been (mostly) liberated by changed TDA 4605, DP6, CP23 and the zener diodes around TDA4605.

Now I am getting the error code pictured. I understand it is a RAM bank failure in Bank B but I’m not sure what the 0400 in the bottom row means. I also don’t know which RAM chip is represented by Bank B. This error appears with or without the memory expansion installed. 
 

I have recapped both the analog and logic boards and any and all electrolytic leak was neutralized with vinegar then rinsed with IPA.

BDACFB59-5557-4E8C-8EED-532FAC78016E.jpeg
Posted by: dochilli on 2020-04-30 06:37:35
There are 1MB RAM on the logic board. One of these chips could be defect. 

The 400 means that bit 8 to 15 showed the error.
1