[RESOLVED] Re: EPROM baking
Mark G Thomas
Mark at Misty.com
Mon Feb 5 12:20:30 CST 2018
Please see resolution below, if you are curious about how this turned out.
On Wed, Dec 20, 2017 at 09:18:50PM -0500, Mark G Thomas via cctalk wrote:
> > On Wed, Dec 13, 2017 at 9:08 AM, Mark G Thomas via cctalk <
> > cctalk at classiccmp.org> wrote:
> > > Hi,
> > >
> > > I am working on several projects requiring 2708 and 2716 EPROMs, and
> > > am finding some of my chips will not erase, and some will not take
> > > a program. I've also learned more in the past week than I wanted
> > > to know about repairing Data-I/O 29a/b programmers.
> > >
> > > I vaguely remember in the 1990s baking such EPROMs in the oven, but
> > > I do not remember temperature or time. I was surprised that Google
> > > didn't turn up anything useful with this info.
> > >
> > > I'm sure someone here will have some notes on EPROM baking.
> > >
> > > Mark
> > Mark,
> > If this is an issue about reviving bad eproms? I assume you have tried the
> > regular stuff.
> > What process are you using now to erase 2708/16's? I have a simple eraser
> > unit and it seems to always work. Some eproms go bad but I never have
> > issues with erasing them. My point is that maybe you need a better prom
> > eraser unit.
> They seem to erase fine, using a PRO-LOG 9103 eraser (box, timer, tube...)
> > I would avoid baking them until you have exhausted other
> > options. Not sure what others think. This topic has come up before here,
> > about putting them outside and all that. The erasers are all over ebay,
> > and the hardware store is full of the correct types of lighting, why not
> > make a box that will do the job? I assume there is more to it that
> > simply erasing them.
> > Bill
After more experimentation I came to the following conclusions.
1) Some of my chips are legitimately bad, erasing fine but won't take a program.
2) Many of the chips were failing to program because my Batronix
programmer apparently requires more current than my USB port provides.
This surprised me because I have been programming chips for years
using this programmer on this computer port successfully, and this
is the first I have had the problem. Using a Anker powered USB hub solved
things. My Batronix programmer even arrived with a cheap powered hub
when I ordered it, but I never used it because it was shipped with an
incompatible wall wart, but looking at it in the box gave me the idea
that this might be the issue.
3) I thought I had ruled out the programmer (#2) because of troubles
programming those same chips using another programmer, but I probably
had the wrong chip type selected, or simply failed on some of the #1
chips so assumed that was my only problem.
Mark G. Thomas (Mark at Misty.com), KC3DRE
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