Re: IIGS - Clock/PRAM chip

["Michael J. Mahon" <mjmahon@aol.com>]

sundown@nwrain.net wrote:
> Thanks for the reply.  Yes the batteries are connected with
> the right polarity.  The clock keeps good time but when I
> turn off the computer it does not save the time or PRAM.
> I am assuming the battery is used to save this info and
> since they are connected properly and good it might be
> the chip but I have no idea what is wrong.

If it were the chip, then it wouldn't work when the computer
is on either.  It has to be between the battery and the chip,
and there are only some wire and a diode, or so.  The diode
could be open, but that would be a rare failure.

Look carefully at how the battery pack is attached to the
board.  I'd be willing to bet that there's a bad connection.

I don't know what kind of wire is used, but it's possible
for the wire to be broken inside the insulation, particularly
if it is thin solid wire.  Perhaps the solder joint is a "cold"
joint, making bad electrical contact.  Perhaps it isn't soldered,
just twisted--which is another place that the contact can be bad.

Do you have a multi-tester or voltmeter?  Or an LED with a
470 Ohm resistor in series?  ;-)  If so, check for the presence
of about +3.6v between the Vcc and Gnd pins of the clock/PRAM
chip.

-michael

NadaNet networking for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."