removing/desoldering an opamp from a pcb but still keeping it alive for use?

[ambulancevoice]

my old 10w bass amp died ages ago (for sure this time), i gutted it, scoring some good shit, and a real nice amp chassis, and i noticed a couple jrc4558's, which i would like to use in a build
but unfortunately, there soldered directly to the board, and i have no idea how to remove them without killing them!

help!?

[John Lyons]

They Are only a 50 cent part so try to get them out...but if not it's no big loss.
Get a solder sucker and remove and much solder as you can.
Use a small screwdriver and lightly pry the chip up while heating the solder pads.
Usually this has to be done to all the pads in fast succession.

You can always heat up the solder side of the board with a propane torch and smack the board against a hard object which will dislodge all the parts that were heated enough to liquify the solder. It does work pretty well.

John

[MikeH]

I use a desoldering iron.  About 10 bucks from radio shack.  Works great for this sort of thing and also if you the mistake-prone type.

[plankspank]

Solder Wick works pretty good here also (it is a copper braid on a roll that absorbs solder pretty much like a sponge to water when heated with the tip of the solder iron.) Use it to get most of the solder off the pads, then wedge a screwdriver between the chip and hit the pads again with the iron...

[ambulancevoice]

thanks

do opamps fry easy?

[niggez]

I use the desoldering wick as well. It works great. And its not expensive at all.

[Mark Hammer]

1) Heat sync the chip so that it doesn't get overheated.  That can be as simple as folding over a piece of paper towel dipped in ice-water and letting it sit on the chip.  Certainly don't apply heat to the joint for too long at any point.

2) Make sure all dust and other crap that can reduce the efficiency of heat transfer from iron to joint is eliminated or reduced.  Sometimes, melting a little solder to the existing joint can help in liquifying what's underneath.

3) Get yourself some liquid flux and some Q-tips (cotton tipped applicators) and wipe a little bit of flux on the joints in question.

4) Use a solder sucker or solder wick.  I used to be a devotee of solder suckers, but there are some jobs they simply don't do as well as solder wick.  Note that there are multiple gauges of solder wick, with some more oriented towards lifting large amounts of solder offlarge solder joints and others oriented towards smaller pads.  I find that a wee bit of liquid flux wiped onto solder wick makes it a real force to be reckoned with; the solder just comes off like gangbusters.

Double-sided PCBs present special challenges since there is a joint on both sides of the board.  My experience is that if you want to salvage the board itself, AND it is double-sided, best to use solder wick.

Depending on the spacing on the board, you may be able to use a small flat-head screw driver to gently pry the chip loose.  If there is ANY question about how the heck you can slide the screwdriver tip under the chip, then use an IC removal tool.

Finally, the chips in question are nothing particularly special.  If it's worth it to you to spend the money on removal tools for future instances, and the time required to remove these chips, fine.  But I can't see going to all the effort and expense if we're really talking about $3 worth of chips in total.

[Albot]

When i gutt stuff for Ic's I usually do it quite violently and just try to snap the pcb right next to the leads with pliers.
Then i use an exacto knife and cut the pcb right next to the leads (if the pliers are not exact enough).
Then just heat one lead at the time and carfully bend it out from the ramaining pcb that's under the chip.

You gotta be kinda carefull though not to snap any leads when you try to demolish the pcb.

I do it all the time though so a gentle touch should make it easy enough.

I don't use the solder braid cause i got such a weak soldering iron so far so i can't heat it propperly, it might be a better idea though.

[miqbal]

I've removed three TL022 DIP and two NJM2068LD SIP on my taiwanese GE-7, installed sockets, then put them back in place. Works fine. Only with a 40 watt solder, a solder sucker, and flux.

keyword: fast,.. but do it gently

PS: I noticed that, fortunately,  probably almost all BOSS PCB have a bit bigger drill holes than standard holes (probably more than 1mm in diameter)

[Gus]

A temp controlled soldering iron
A solder remover like the Soldapullt DS017 OR good solderwick

OR

A good desoldering station

The most important part  PRACTICE

[Dai H.]

all you need is a soldering iron (say 30watts--no need for it to be temp. controlled IMO) and some solder-wick (fluxed copper braid) and decent technique. One pin at a time. Wait 30 secs. between pins for extra safety. You could "cheat" also if you can find something to act as a heatsink (say, tweezers thin enough to fit on a pin with a rubber band around it)--this would buy you a bit more time.

[ambulancevoice]

ok, thanks for all the advice
what ill is, get a adhesive back thermally transparent heat sink, mount it on the ic
then desolder each pin with solder wick, taking a a period of time bettween each pin
then using a jewellers screw driver, pry the ic out

[petemoore]

  On up to 8 pin IC's.
  Prying up on one corner, and heating those two pins nearest until solder just 'ticks' to indicate the joint moved, getting a tteeny bit of movement on the center pin even though you can't always feel it move.
  Repeat on other sides corner while prying there, then work on the left side while the right side still is held still because it's only partially removed.
  Pulling with thumb and forefinger [thumbnail actually does the pry-pulling against the board] and holding the board, running the soldering iron down the row of 4 leads on one side, usually that side pops right out, usually.
  The other side comes out pretty easy at that point.
  Never really baking anything, and allowing cooling times between the solder/  joint movements.

[Dragonfly]

I think RG has the best method !

http://www.diystompboxes.com/smfforum/index.php?topic=51189.0

[caress]

  Pulling with thumb and forefinger [thumbnail actually does the pry-pulling against the board] and holding the board, running the soldering iron down the row of 4 leads on one side, usually that side pops right out, usually.

i've gotten a few ics stuck in my fingers using that method...  not fun pulling them out.   

i say just buy new ones.  you can get a batch of 10 on ebay for $3... not worth the effort unless it's an obscure or expensive chip imo.

[drewl]

MY GOD...man....put away your butcher knives and let me save this patient!!!

I often salvage parts from old stuff, even multi-pin flat smd devices from new stuff....
anyway, most of these old devices are pretty rugged.
get yourself some flux and solder wick at RatShack and desolder the pins and carefully remove the device.
it ain't rocket science.
try not to over heat.

[ambulancevoice]

wow, so many ideas
R.G.'s method doesnt sound to bad, but i dont have a flamethrower or heatgun

i dont wanna buy the ics cause im trying to save as much money has possible, so i can fund more complicated future projects
at the moment im savaging parts for some fun builds, and i really dont wanna waste my money on them

looks like i just go with what i said before

[Dai H.]

another thing that that sometimes a couple of the IC's pins are bent up against the board. This makes it a bit more of a pain.

For R.G's torch, maybe a butane-powered soldering iron (in "torch mode" with no tip and the torch tip attachment) will work.

[JasonG]

RG thats great 
Well I just picked up one of those RS De soldering Irons. MAN, why didn't I buy one of these years ago? I have too much money in my soldering iron to waist the tips on de soldiering. For the cost of a tip I got a whole iron and it made the job way easier.

[jefe]

Even though these types of parts are very inexpensive to buy, there's something very cool about salvaging old ones. I once picked a toy keyboard out of someone's trash, and found a JRC386 in there. Desoldered it and turned it into a Ruby amp.