Roger,

On 4/08/2010 7:38 PM, Roger Weichert wrote:
> I remember having this problem many years ago with eproms.
>> Just erase them again, let them cool and program again.
>> David...
> I really really hope that's it.
> Thanks for the encouragement.
> Regards, Roger
>
Depending on the exact eprom type, definitely  make sure you follow=20
correct anti-static CMOS handling procedures.
Ensure the eproms are evenly spaced in the UV eraser, and yes there is a=20
settling time,
both temperature and removal from the UV light.
Use conductive foam material in UV eraser.

Sometimes, exercising the eprom with cycle bits, eg. all FFFFF's erase=20
and all 00000's then erase again.  If they fail they are stuffed.

However from my experience with lost of eproms, over the years, they are=20
more robust then you think.
So-long-as you follow correct CMOS handling procedures.

Robustness also does depend on brand!

Peter
--=20
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