Notice, he's wisely replaced them with sockets. But I have a stack of failed 128K boards all with Apple-branded, Sad Mac RAM error codes in need of replacement. Yet I have never seen a third party OEM RAM chip that's failed. Could just be my experience but I think it is more than coincidence. Apple must have gotten quite the deal on some really cheaply made RAM,
Thanks 128, I'm the one who did the repair, I traded my brother for a Bad Lisa board
He's pretty good at that stuff but he had fried his new chips because he refuses to use sockets (just a little heat over a 15w iron destroys those things), in fact I have the board back because after you would start it 7 or 8 times (and that is almost to a T) you get an error code for those chip locations, I believe it is because of the different chip speed, this has happened on probably a dozen of the boards I have repaired? In theory the RAM will only operate as fast as the slowest chip, HOWEVER, when I have used the correct 200ns 4264 equivalents I get no error codes(And this is in probably over 30 boards)? the error codes go away after a restart on the the boards where I used the 100ns and 150ns chips, and they would once in a very great while generate a system error when using MacPaint, but not with the other programs. The chips I had been using were 100ns and 150ns, the 150ns seem to generate less error codes than the 100ns (probably 10 to 15 starts). As far as Apple cutting corners I would have to disagree, I have seen Apple branded chips from three manufactures, I believe Apple simply screen sprayed these chips when they received them, I have seen at least two logicboards with 200ns chips from two different manufacturers (MT4264 and 3764) that are Apple branded? One last thing about the 040002 code, MAC128 is right .........for some reason every time I have an error code there or at G7, the F7 or G8 chips are kaput? As far as the test using chips piggybacked onto "supposedly" failed chips, I have heard this from many techs as far back as 1983, but in my experience it does not work. if you sandpaper the legs of the chip in question and the chip you piggyback, and squeeze them really tight, you might get a connection that will suffice for data transfer (and yes I know what folks will say about the clip on memory upgrades) , BUT, again in my experience it simply does not work, I had numerous chip failures only to go through all the banks and find that the chips I had been using for testing were bad, OR, the chips I had been using were good, but not making a good connection, sockets are the only way to go. I also believe that even if you piggyback the chip in question, it is still cycling data through (the old chip) and will still show the same error? I have ran into this before.
