Re: IIGS - Clock/PRAM chip

["Polymorph" <polymorph69@hotmail.com>]

On Feb 16, 6:49 pm, "Henry" <apl2research(.a.t.)comcast.net> wrote:
> Hey Michael.
>
> May I ask what is the location of the PRAM in the IIgs?  I can't seem to
> find where the battery traces go.
>
> I have some dead IIgs Motherboards here.  Maybe I can pull the IC and send
> them to John and Polymorph.
>
> John:  I can always send some new connectors for the battery pack if you
> want to try that.
>
> --
> Henry S. Courbiswww.ReactiveLegacySystems.comwww.GSE-Reactive.com
> Legacy Hardware and Support - Come take a look at what we have to offer!
>
> "Michael J. Mahon" <mjma...@aol.com> wrote in messagec4idnVTPZIEHnEjYnZ2dnUVZ_qOpnZ2d@comcast.com">news:c4idnVTPZIEHnEjYnZ2dnUVZ_qOpnZ2d@comcast.com...
>
> > sund...@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."

Henry,

if I'm not mistaken, the PRAM / Clock Chip is marked as "Ser Clock"
and is situated right next to the VGC chip - just to the back and
right of it (looking from the front).

Probably not worth the trouble in my case as I'm in Australia -
besides, I've since acquired a fully working ROM01, so that will keep
me out of trouble for now.  ;-)

If John continues having trouble he might benefit from your offer,
although as the chip is surface mount, it would take someone quite
experienced with a soldering iron to replace the chip.

Thanks heaps for the offer though! (and keep up the good work, I like
the new web design).

cheers,
-p