Path: utzoo!attcan!uunet!tank!ncar!boulder!sunybcs!dsinc!unix.cis.pitt.edu!fmgst
From: fmgst@unix.cis.pitt.edu (Filip Gieszczykiewicz)
Newsgroups: sci.electronics
Subject: tip for some...
Message-ID: <24655@unix.cis.pitt.edu>
Date: 2 Jun 90 05:57:45 GMT
Reply-To: fmgst@unix.cis.pitt.edu (Filip Gieszczykiewicz)
Distribution: all
Organization: The Last Jedi
Lines: 56


	Greetings. I think that this subject has had all its
	life shaken out of it but here goes:


	A few days ago I got a 250W INFA-RED lamp (for $3.95)

	I put a mainframe board 1 inch from the bulb and turned
	the power ON. (remember 8 layer boards....)

	In 2 minutes I was able to use a chip puller to "yank"
	the chips from the component side. Neat!!!!

	That's not the punchline....


	2 things for best effect:

	1) Get a candle and deposit some carbon on the solder
	that you want to melt... (hold the board solder side
	down over the candle...) That way you can reduce the
	exposure time and also heat up maximaly only the area
	you want.

	2) Make a series of IR-absorbent-glass slides that have 
	a pattern "H" without the "-" bar.. make them in sizes of all
	the DIPs that you have on those boards... That way,
	you do not damage the board...


	IT WORKS. WE USE IT TO FIX VCR, TV, AND RADIO (and computers)
	in a repair shop I know... sure beats cutting the leads and
	unsoldering each pin... or using the "shitty" usoldering
	vaccum pump... or used a BLOW-TORCH (I have seen.... )

	By the way, if you use the slides, make sure they are
	IR absorbent glass and that they are GLASS or METAL. You'd
	be suprised how much heat 250Watts is.... 


	Sum up: If used properly with proper slides, one can remove
	even the "deathly" PGA and the 48 pin DIPs WITHOUT damaging
	the board or plated holes (which are a pain... as you've
	read here...) 


	Take care. 

	P.S. I have a feeling that someone may put me on a 
	"black list" for revealing this one ;-)

-- 
_______________________________________________________________________________
"The Force will be with you, always." It _is_ with me and has been for 10 years
Filip Gieszczykiewicz "..of future fame...." "Ok! So I have a dream..."
FMGST@PITTVMS  or  fmgst@unix.cis.pitt.edu "My ideas. ALL MINE!!"