Re: Apple II+ problem

[pausch@saaf.se (Paul Schlyter)]

In article <42cf874d$1_3@newsfeed.slurp.net>,
Ryan Smith <nospam@nospam.nospam> wrote:

> I've just bought a complete Apple II+ system (48K, language card,
> four Disk II drives, Disk II controller card, Epson MX-80 printer with
> interface card, Zenith monochrome monitor, lots of disks) at a yard
> sale, all for $6.
> 
> When powered on, the machine only displays a screen full of this:
> 
> ))VV))VV))VV))VV))VV))VV))VV))VV))VV))VV
> 
> This repeats to the bottom of the screen. The V's are inverse (black
> on green) and the parentheses are normal (green on black). The
> keyboard does nothing. The drives do not spin.
> 
> I've already tried re-seating all of the socketed ICs on the main board.
> I've tried booting with all of the accessory cards removed, and with the
> keyboard disconnected. Nothing works.
> 
> Any ideas? I have no experience with the Apple II, other than playing
> math games on one in third grade. I just bought it because it was cheap
> and I thought it might be fun to play with. I always wanted an Apple when
> I was a kid, but all I got was a TI-99/4A :(

Obviously you have some kind of motherboard problem.  Perhaps some of
the chips of the motherboard is broken?

One thing you could try os to remove all RAM chips except the lowest
row.  If your Apple II still doesn't work, try to exchange the
remaining RAM chips on the motherboard with RAM chips you've removed
- that row contains the addresses of the 6502 page zero and stack,
the video memory, etc, and if it's not present the Apple II won't
work at all.

If that doesn't help, bad RAM chips is probably not the problem.
And I suppose you have no spare chips -- well, the best you could to
is to look for another Apple II.  This time you only need the
computer itself - no peripherals.  If that computer works, use it
instead.  If neither of them works, try to exchange chips to see if you
can get at least one of them to work.

Another thing you could do is to measure the voltage from the power
supply.  It's supposed to deliver +12V, -12V, +5V and -5V.  If any of
these voltages is missing, then that's a most likely explanation of
the failure of your Apple II.  If so, the power supply needs to be
replaced.

Good luck!

-- 
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