9 Jan
2003
9 Jan
'03
1:52 p.m.
"Richard A. Cini" wrote:
Anyway, I'm having diskette issues. I have two theoretically good
single-density controllers and disk drives, and Don Maslin made replacement
boot disks for me. These disks don't boot, although the controller attempts
to access them. It may be that the replacement SD disks were made from a DD
controller, but I don't know for sure.
So, I have two choices -- obtain SD boot diskettes made with an SD
controller or get a N* DD controller (MDS-AD|AD2|AD3). Any other thoughts or
recommendations appreciated. Thanks.
I have a similar problem with three of my N* computers, and finally
decided to find out what was going on. The DC voltages were okay and
there only appeared to be about .2 VAC ripple on the line; I think that
is okay. By doing board swaps, I found out the CPU and MDS cards were
good and the disk light would come on w/o any memory installed.
Interesting! One of the memory cards appears to be bad. Doing board
swaps to a good machine and everything works. I am down to one of two
things, either the motherboard has some problems, or the memory card is
bad. I was using 64K RAM boards, and since I didn't pull out the docs to
double check, it is possible the "bad" ram card had the E800 segment
turned on (that is the location of the N* boot routines.) Yes, I did
swap disk drives also in the process.
Did I mention that I heard a couple of "pops" on the CPU card when
apparently the tantalum caps shorted and exploded :). One of the CPU
cards had a trace burn off when the cap went.