Re: IIe faulty RAM ?

[waynes@intergate.ca (Wayne Stewart)]

Mark Cummings wrote
> I am suspicious of the soldered in RAM, which is 2 of 41464C-10. Before I go
> desoldering, can anyone shed any experience with RAM faults and the
> symptoms.

I haven't had a problem with a platinum IIe but I've had Ram problems in other
enhanced IIes. Random characters on the screen was one of the symptoms I 
encountered in some units. My impression is that what you get depends on how 
bad the RAM is and where it's faulty. In the worst case I had a screen that 
was mostly white blocks and a squeal coming out of the speaker.
 
> Would the inbuilt diagnostics (Ctrl-Option-Reset) run correctly if the RAM
> was faulty, if so how would it display the result, since the text screen is
> memory mapped.

The self test does test the RAM and and shows where the bad RAM is provided it 
will run at all. If the RAM is dead or bad in the wrong spot then the self-test 
won't work.

> Also, should it still make any sounds, as this would be
> addressed outside of RAM space ?

I know it can still make sounds or at least squeals with very dead RAM. Whether 
that applies in all cases I don't know. My personal experience is limited to 
only about 20 or so IIes with bad RAM.


	Wayne