Sad Mac Code 040002

[retrobecanes]

A few months ago I bought a NOS Mac 128K mobo.  I installed it and it worked perfectly well.  After a couple of weeks, I put the computer away in storage as I was working on other computers.  Today, I take the Mac 128 out of storage to give it a spin, I power it up and I immediately get the sad Mac code 040002.  Based on the code list, it appears to be a failure in the memory chip at location F2...great!  I guess that I will have to take this opportunity to have all the memory chips socketed and replaced.  But I have a quick question: does RAM just go bad like this or could it be a power/PSU that fried the memory?

 

[IlikeTech]

The chips are very old, so the chips may just be bad. Try replacing it, and if it blows again, then maybe the power supply is at fault.

 

[BadGoldEagle]

If it has the original Apple RAM, then you'll have to replace all of those RAM ICs. The RAM Apple used on the 128k macs is trash.

When I bought my 128k, I also had to replace the RAM. Uniserver can do it. Link to his website: http://www.maccaps.com/MacCaps/For-Sale.html 

Uniserver told me that he used to replace one RAM chip at a time but he also told me that the same person kept sending him the same board over and over again because all the old chips failed one at a time. So he prefers to change them all at once nowadays.

Although $175 seems a little steep, it is well worth it because the new RAM will last a lifetime. Apparently it is very difficult to desolder the chips as there are a lot of traces in that region that could be destroyed very easily (according to him).