Re: Apple ][+ gravely ill - seeking assistance :(

["N.N. Thayer" <nnthayer@hotmail.com>]

On May 31, 11:05 am, "N.N. Thayer" <nntha...@hotmail.com> wrote:
> On May 30, 8:20 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
>
>
>
> > N N Thayer wrote:
> > >   To: N N  Thayer
> > > From: N.N..Tha...@familynet-international.net
>
> > > Whoa. I'd originally deleted this message, yet here it is again...
> > > -+- SBBSecho 2.12-Win32
> > >  + Origin: Derby City BBS - Louisville, KY - derbycitybbs.com (1:2320/100)
>
> > > --- BBBS/NT v4.01 Flag-5
> > >  # Origin: FamilyNet Sponsored byhttp://www.christian-wellness.net(8:8/2)
> > >  * Origin: FamilyNet Echogate [972] 496-0650 (1:124/5009)
> > > --- Synchronet 3.15a-Win32 NewsLink 1.85
> > >  *  Derby City Online - Louisville, KY - telnet://derbycitybbs.com
>
> > There's nothing you can do about the repeats.
>
> > The BBS sysop has a configuration problem and apparently doesn't
> > realize he's echoing posts...   ;-(
>
> > BTW, just try replacing memory chips--or, if you're lucky, try
> > bending the pins in a bit on a good memory chip and "piggybacking"
> > it on each memory chip in turn to see if you can get it working.
>
> > The one you piggybacked when it worked is the bad one.
>
> > (This doesn't always work, depending on the chip failure mode,
> > but when it does, it saves a lot of time.  ;-)
>
> > There are, of course, other possibilities, but trying the most
> > likely things first makes most sense.
>
> > -michael
>
> > AppleCrate: An Apple II "blade server"!
> > Home page:  http://members.aol.com/MJMahon/
>
> > "The wastebasket is our most important design
> > tool--and it's seriously underused."
>
> FIXED.  (As far as I can tell.)
>
> Since I couldn't even reset, I replaced the F8 ROM with one from a
> Language Card I had sitting around, and presto!
>
> Oddly, this is the second ][/][+ class machine I've had on which that
> specific chip has gone bad - I had a Rev 1 ][ some years ago on which
> I had to perform the same fix.  I might pick up a spare ][+
> motherboard just on general principles.
>
> Being able to repair a computer yourself, replacing only what's
> broken, as facilitated by the machine's design, is an incomparable
> thrill.  I felt the same way when I recently replaced the power supply
> in my PC (that I had admittedly skimped on).

Hmmm.  Well, now I can get to a prompt and work there indefinitely,
but if I try to load anything off a disk, including ones that I know
are self-bootable, I get garbage characters and the drive simply
spins.

I've swapped disk controller cards, and tested the drives on another
machine, so I know it's not either of those.

Prior to this, I was able to keep the computer up long enough to write
an image of the Apple ][+ Diagnostics disk from Asimov and run RAM/ROM
tests - and both checked out fine.  I haven't yet tried replacing RAM
chips.