[Gmecm] REPLACING vs. Erasing EPROMs

[Rick McLeod]

I agree w/ both of these points of view:
1) even though eprom technology is antiquated, it
still works, quite well, in fact, so if the imbedded
base is significant it may (as w/ the person w/ 3000
devices) feasable to replace

2) if you do decide to replace, DON'T attempt to
desolder and remove the old chip intact, you risk
damage to the board that can be avoided! instead,
sacrafice the old device! Use a micro-shear type
cutter and file the point to make it narrow enough to
fit between the adjacent pins of the chip right next
to the chip body, and snip each pin flush w/ the body
of the old chip. This allows to remove each pin
individually, a quick touch w/ an iron and it will
lift right out, I use a scribe to hold the pin against
the iron tip, and lift both together with the pin
between the iron and the scribe, takes a little
technique development, so get a scrap computer board
and practice first. When all the pins are removed, it
is simple to either wick or sip the remaining solder
from the holes (carefully) and then install the new
device (or ZIF) and resolder in place.
I have sucessfully used this technique to replace
chips on very expensive circuit boards, even
multi-layer boards where it is cruicial to not damage
the eyelet plating as that is the only connection to
the middle layer traces!

Good luck, be careful, but in this case sacrafice is
goodness!
--- William Lucke <william.lucke at highspeedlink.net>
wrote:
> That sounds great! You wanna unsolder a pair of 28
> pin chips from each 
> carrier so I can replace them with EE's?
> :P
> 
> 
> Will
> 
> 
> >From: <ahuxtable at sola.com.au>
> >Subject: RE: [Gmecm] Erasing EPROMs
> >
> >Mine takes <2ms to erase....
> >
> >Pfft, EPROMS - Get with the times EEPROMS are the
> go.
> >
> >Andrew
> 
> 
> 
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