Dave
Guest
Tue Aug 05, 2008 9:04 pm
Once upon a time someone posted that they had found something that really
brought out the numbers etc on otherwise difficult to read ICs.
Unfortunately I didn't save the post, or the info in it. Anybody have any
ideas on what this might have been, or how to read those invisible
numbers/letters? Some ICs are no problem, but others... I am getting
really tired of trying to get the light just right and halfway guessing at
what they say.
TIA,
Dave
John Fields
Guest
Wed Aug 06, 2008 12:06 am
On Tue, 5 Aug 2008 16:04:15 -0500, "Dave" <db5151_at_hotmail.com> wrote:
Quote:
Once upon a time someone posted that they had found something that really
brought out the numbers etc on otherwise difficult to read ICs.
Unfortunately I didn't save the post, or the info in it. Anybody have any
ideas on what this might have been, or how to read those invisible
numbers/letters? Some ICs are no problem, but others... I am getting
really tired of trying to get the light just right and halfway guessing at
what they say.
---
http://www.doneganoptical.com/optivisor.php
JF
Dave
Guest
Wed Aug 06, 2008 1:33 am
"John Fields" <jfields_at_austininstruments.com> wrote in message
news:cmqh945a9qems4hqtl4ki8io77f6f0n254_at_4ax.com...
Quote:
On Tue, 5 Aug 2008 16:04:15 -0500, "Dave" <db5151_at_hotmail.com> wrote:
Once upon a time someone posted that they had found something that really
brought out the numbers etc on otherwise difficult to read ICs.
Unfortunately I didn't save the post, or the info in it. Anybody have any
ideas on what this might have been, or how to read those invisible
numbers/letters? Some ICs are no problem, but others... I am getting
really tired of trying to get the light just right and halfway guessing at
what they say.
---
http://www.doneganoptical.com/optivisor.php
JF
Thanks, but I already have a magnifier that will do the job if I choose to
use it. Would rather have something that does the job once and for all on
each unreadable IC. I'll try google again...
Dave
Dave
Guest
Wed Aug 06, 2008 3:56 am
"JeffM" <jeffm__at_email.com> wrote in message
news:7bf990cc-e54f-44c8-b7e3-d08c569382e0_at_r66g2000hsg.googlegroups.com...
Quote:
YES! That was it! THANK YOU!
I had some teflon tape handy, and tried it out, and it works like magic.
For me, laying a strip of tape over the IC of intersest and rubing fairly
lightly with the ball of my index finger brought the letters and numbers,
including the manufacturers logo (which I didn't even know was there) out
like magic. Peeling the tape back off, the letters and numbers were still
there, and highly visible. Thank you again. I have another trick in my
toolkit now.
Dave
JeffM
Guest
Wed Aug 06, 2008 5:37 am
Dave wrote:
Quote:
Once upon a time someone posted that they had found something that
really brought out the numbers etc on otherwise difficult to read ICs.
Unfortunately I didn't save the post, or the info in it.
Nigel Cook mentioned teflon tape:
http://groups.google.com/group/sci.electronics.repair/browse_frm/thread/10537b1a1507d8d9?q=*-*-*-*-*-*-show-as-clear+*-missing-characters-came-up-*-*+*-*-rubs-*-without-dragging+Don't+zzz+wooden+wrapped-in-*-*-*-PTFE+rubbed+PTFE.tape
news:fk5p1n$3ne$1_at_inews.gazeta.pl
Dave
Guest
Thu Aug 07, 2008 1:56 am
"Dave" <db5151_at_hotmail.com> wrote in message
news:39WdndkUXqRtvQTVnZ2dnUVZ_qninZ2d_at_posted.internetamerica...
Quote:
Follow up-on some ICs you have to rub with the back of a nail or other
rounded, smooth surface, to get an image of the letters/numbers in the
teflon tape. Then the image is in the tape, and not on the IC, like the
original poster (Nigel Cook) said. But it still works! Damn.
Thanks again,
Dave
Jasen Betts
Guest
Thu Aug 07, 2008 9:48 am
On 2008-08-05, Dave <db5151_at_hotmail.com> wrote:
Quote:
Once upon a time someone posted that they had found something that really
brought out the numbers etc on otherwise difficult to read ICs.
Unfortunately I didn't save the post, or the info in it. Anybody have any
ideas on what this might have been, or how to read those invisible
numbers/letters? Some ICs are no problem, but others... I am getting
really tired of trying to get the light just right and halfway guessing at
what they say.
high brightness LEDS and low angle lighting are two tricks I use.
a magnifier helps too.
Bye.
Jasen
Tom
Guest
Fri Aug 08, 2008 2:28 am
On Tue, 5 Aug 2008 20:37:38 -0700 (PDT), JeffM <jeffm__at_email.com>
wrote:
Quote:
That's a great tip. I have to try that sometime. Thanks.
Tom
N Cook
Guest
Sat Aug 16, 2008 11:36 am
Dave <db5151_at_hotmail.com> wrote in message
news:peednfLHm4PLXQXVnZ2dnUVZ_sDinZ2d_at_posted.internetamerica...
Quote:
Once upon a time someone posted that they had found something that really
brought out the numbers etc on otherwise difficult to read ICs.
Unfortunately I didn't save the post, or the info in it. Anybody have any
ideas on what this might have been, or how to read those invisible
numbers/letters? Some ICs are no problem, but others... I am getting
really tired of trying to get the light just right and halfway guessing at
what they say.
TIA,
Dave
from one of my tips files, off URL below
How to read unreadable IC/transistor lettering
Yes, just like magic.
I could not read 3 of the 5 characters on a heat damaged TOP66 power
transistor.
I wondered if a sort of "brass rubbing" would work.
I just happened to have some plummer's PTFE tape to hand ( nominal 0.05 to
0.08 mm thick).
Laid a piece over the power tranny, rubbed with a finger nail, and the
missing characters
came up like magic.
As the characters remained on the PTFE, as an image , I realised you could
use this technique to read IC lettering where it is imppossible to read,
because of constrictions and inability to introduce an inspection mirror or
even just
where you cannot get the illumination at just the right angle to read.
You need access space enough to introduce a piece of PTFE and then rub it
with the wooden end of a small artist's brush, or similar, wrapped in some
of the PTFE, so it rubs easily without dragging.
Don't rub too firmly because you want the relief print to show as clear and
the rest of the PTFE becoming translucent rather than the original white.
Remove and read with a backlight or against something matt black. Maybe a
couple of attempts to get a clear image in all parts of the label.
May even be worth trying on reverse-engineering-proofed, rubbed off, IC
lettering. Useful for indistinct moulding logos /
lettering etc on small plastic parts, gives some contrast.
--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
