Re: How to fix a Disk ][ 5.25 drive?

[powergs@macgui.com (Sam Latella)]

Where can I purchase this chip?

Thanks for everyone's help!

Sam


Linards Ticmanis wrote:
> On 12/19/2010 06:32 PM, Sam Latella wrote:
>> Looks like my disk ][ has bitten the dust?  The drive light comes on and
>> now
>> just spins without reading anything on the 5.25 disk.  Any quick solution
>> for a fix?  Would like to keep this drive working with not much cost.
>> 
>> Thanks in advance.
> 
> Firstly, absolutely don't put any important disks in there until the
> drive is fixed, and verified as fixed. Apple drives have a fairly common
> failure mode that causes them to be constantly in write mode, so that
> it's unable to read or boot from disks and will overwrite any disk you
> put in, even if it's write protected.
> 
> To fix a drive in this state, you'll need to replace the 74LS125 chip
> that's inside the drive. Luckily this is a cheap and easy-to-get chip.
> 
> To prevent this failure mode from occurring in the first place, always,
> when you plug the drive cable into the Disk II interface card, before
> turning power on, make absolutely sure you didn't misalign the
> connector. The fault is caused by sending 12 Volts to a line that's only
> meant to handle 5 Volts.
>