Apple 2e PAL, self test problem.

RAM message.png

If this is the display message you get. I think it's a faulty RAM  chip (postion F3) the first RAM chip on the lefthand side as viewed  with the keyboard in front of you.

I had the same problem.

Good Luck

You should consider upgrading your IIe with an enhancement kit.

You'll improve compatibility across a lot of software, and the newer built-in self test gives you a bit more information on the RAM situation if there is a RAM fault, which is what your self-test is telling you now.

If you look at your RAM chips and they have the MT logo on them, the fix is to replace all of them.  MT chips are known to have age related issues.

baldrick wrote:

 

You should consider upgrading your IIe with an enhancement kit.

You'll improve compatibility across a lot of software, and the newer built-in self test gives you a bit more information on the RAM situation if there is a RAM fault, which is what your self-test is telling you now.

 

If you look at your RAM chips and they have the MT logo on them, the fix is to

The lazy man's approach to replacing RAM chips when the self test fails without identifying which chip it is would be to start from the direction the errors normally display from and replace each chip and re-test until either all are done or it starts to work or at least starts to report which chip it thinks is bad.

And of course, remove the chips and replace with a quality socket.  I usually remove chips that I don't worry about re-using by clupping the pins and then they are easy to remove one at a time.

But yeah, some brands of memory seem to fail more often, and the MT memory that Apple used a lot in //e units has about the worst reputation of any.

If it isn't the RAM itself it could be the MMU.  Or possibly just the MMU socket (hopefully it is socketed).  MMU chips are currently unobtanium but hopefully before too long modern CPLD/FPGA based replacements will be available.  I have run into two //e motherboards in the past couple years that just had faulty MMU sockets though.  A lot of the sockets Apple used back then were kinda crappy.

I do agree that the Enhancement kit is worth it though.