EPROM Death?

[Allison]

>
>Subject: EPROM Death?
>   From: "Zane H. Healy" <healyzh at aracnet.com>
>   Date: Tue, 02 Oct 2007 17:33:11 -0700
>     To: classiccmp at classiccmp.org
>
>How do you tell an over-erased EPROM?
>
>I finally have my programmer and eraser, and just tried erasing 6 
>EPROM's.  Four erased just fine, and two are showing weird patterns 
>of alternating blocks of 04/06 and 14/16.
>
>		Zane
>
I've seen that when the quartz window isn't really clean and the 
UV hasn't quite done the full job.  I have found some vendors 
eproms need a little more time to cook.

Ove 26 years I think I've only seen one that really had a stuck
bit and that was a blown output pin.


Allison