Re: Apple //c displays black and white stripes

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

SbM wrote:
> BluPhoenyx <bluphoenyx@a2central.com.remove-lha-this> wrote:
>
>
> >  To: sebastienmarty
> > sebastienmarty wrote:
> >
> > > Hi !
> > >
> > > I've got a //c here that only displays horizontal black and white
> > > stripes on the screen when I switch it on (well they look black and
> > > white through the composite output), with little twinkling dots
> > > everywhere. It doesn't boot at all with a disk inserted.
> > >
> > > Anybody got a clue what's wrong ?
> >
> > First suggestion is to open her up and re-seat all the chips which are
> > socketed.
>
>
> Did that.
>
>
> > Beyond that, it could be a bad ram or other ic.
>
>
> One of my friend told me the same : probably a bad ram chip... Well, I
> guess I'll have to "unsolder" all of them to track down the culprit...
> :-/

Something that sometimes works (depending on the fault) is to simply
"bridge" a good memory IC over each suspect memory IC and re-test.

This is done by bending the good IC's "legs" in a bit, so that they
make good contact with the exposed part of the soldered IC's legs
(keeping the pin 1 notch/mark aligned with the bridged IC, of course).

If it works, this will identify the bad chip without having to unsolder
a bunch of good ones.

-michael

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Home page:  http://members.aol.com/MJMahon/

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