cleaning a flaky ZIF socket?

[mightyohm]

The ZIF socket on my AVR Dragon is quite a few years old and has become really intermittent/flaky.  Is there any way to clean ZIF sockets?  I can't see any obvious way to open it up, and I sprayed some contact cleaner into it but that didn't help much.

Any ideas?

[SgtRock]

Dear Mightyohm:
--Your might try DeoxIT D100L. D100L has oleic acid (which is only very slightly acidic) in it. It can often be helpful with intermittent connections. Get the drops, not the spray. Put a little bit on a thin pipe cleaner and push in out of the sockets, leave for an hour or so, then clean sockets with a dry pipe cleaner. Try not to get it on anything else. It will not hurt anything, but it can attract dust and pollution, and make high resistance leakage paths, much like anything. If you do, you can clean with high purity isopropyl alcohol. Follow up with DeoxIT Gold to shield surfaces from further oxidation. Best Regards
Clear Ether

[Bored@Work]

All AVRs are in-circuit-programmable. You could drop the habit of programming them in a ZIF socked and instead go the in-circuit-programming way.

If you want to stay with the ZIF socked, replace it. You can spend a fortune on sprays and chemistry and black magic.  And you can spend days spraying and cleaning and waving a dead chicken over it. In the end it won't last long and the old ZIF socket will soon be back playing the same tricks. And there is nothing worse than a tool playing tricks.

A good new ZIF socket is what? $10, $15? Add to that the cost of a normal socket, and then you do the old trick. Desolder the old broken ZIF socket, replace it with the normal socket. Then plug the new ZIF socket into the normal socket. And fix the ZIF socket to the normal socket with hot glue. Next time the ZIF socket breaks you just remove the hot glue, unplug the ZIF socket and plug in a new one. Until, of course, the normal socket wears out, too. Then you once again need to get the desoldering pump out.

[SgtRock]

Dear Mightyohm:
--With regard to the previous comments by BoredAtWork. Please note I did not advocate sprays (one which you already tried), dead chickens or Black Magic. My advice was strictly confined to the problem of oxidation. If the problem is mechanical in nature then obviously a new socket would be the thing to try.

--Sockets are notorious for causing trouble. Plugging one into another doubles your chances of an intermittent open. Nonetheless I would consider trying it. The point of my advice was to give you something to try short of desoldering a socket, and taking a chance of making the PCB unusable.

--The procedure I recommended in my first post should take about 15 minutes, rather than days. I have used DL100 and can testify that it often improves metal to metal conduction. If the problem lies elsewhere, it cannot help. It is used by a lot of professionals. Check it out on the Web and ask your friends. I think you will find it is not in the same class as dead chickens or Black Magic. Best Regards
Clear Ether

[Zero999]

--Sockets are notorious for causing trouble. Plugging one into another doubles your chances of an intermittent open. Nonetheless I would consider trying it.

Sockets normally only fail when they're repeatedly having components inserted inot and ejected from them.  The socket holding the ZIF is less likely to fail because it continuously holds a component, rather than having its contacts wear out.

[SgtRock]

Dear Hero999:
--You stated:

"Sockets normally only fail when they're repeatedly having components inserted inot [sic] and ejected from them.  The socket holding the ZIF is less likely to fail because it continuously holds a component, rather than having its contacts wear out.

--I completely agree. This technique is used frequently in tube testers. "Socket savers" are often used in tube testers to prolong the life of the socket and to avoid ugly re-soldering jobs in crowded layouts with little slack wire available. I think that was exactly the point that BoredAtWork was making. My comments were more addressed to oxidation issues rather than destruction by repeated use. I have seen many cases where equipment with multiple standard sockets showed intermittent (flaky) problems. Sometimes these were cured by simply removing and re-inserting the chips. I have read in various forums this same story countless times. I have also read reports of individuals, and even manufacturers discarding the sockets entirely (standard not ZIF),  and soldering directly to the PCB to avoid this problem.

--If you only have one ZIF socket on a board, and you are faced with removing and re-soldering anyway, then I think as I said previously:

"I would consider trying it"

--I regret any confusion I may have caused by not stating all of this more clearly to begin with.

To Mightyohm:
--If you do not want to or cannot use in circuit programming as advocated by BoredAtWork, then by all means solder in a new standard socket and insert a ZIF as BAW suggests, or solder in a new ZIF, as you like. But make sure that soldering is absolutely necessary, because there are risks involved.Best Regards
Clear Ether

[Milacron]

Not sure if it's ideal for this situation and it's expensive, but in spite of the suspect theories of how it how it works,  Stabilant actually does work...

http://www.amazon.com/Stabilant-22-15ml-Kit-Concentrate/dp/B001E53PG6/ref=sr_1_1?ie=UTF8&qid=1314266376&sr=8-1

[mightyohm]

Thanks for all of the replies.

SgtRock and Milacron - thanks for the suggestions on cleaners.  Both of the ones mentioned are quite expensive (particularly Stabilant), costing more than a new socket.  I guess I need to trade this off against the possibility of destroying the Dragon by trying to remove the ZIF.

BoredatWork - In this case, using the ZIF is preferable, because I am preparing kits and want to program loose ICs.  The socket-on-a-socket approach would have saved me from having to desolder this ZIF socket if all else fails, so that might have been a good idea.  However, I have tried this approach before, and ran into an issue - on my PIC programmer, the force of opening the lever on ZIF socket was enough to bump the ZIF out of the IC socket it was sitting in - so I had to hold the ZIF socket in place to keep it from coming off - not so good. 

I agree that a new socket is the "right" way to fix this.  However, desoldering a big 40 pin DIP is a daunting task for me, as I don't have a proper vacuum desoldering iron, and I'm not going to buy one just for this task unless someone can convince me it is worth the expense in the long run.  So if I do try to desolder the ZIF there is a decent chance I will damage the Dragon, and then I'm out $50 plus the cost of the ZIF.  So then I'm back where I started, looking at cleaners and other in situ fixes again.   

[Mechatrommer]

unless there's visible significant amount of rust, maybe the problem is not the "cleaning solution at all". suggestion for closer inspection on the real problem i propose, maybe loosen/weared pin ie out of position prohibiting spring from forcing the mcu pin into contact with the pin on the other side which is connected to the pcb. maybe pushing the pin back into position "might" solve the problem, no need "fortunated" cleaner or dead chicken. do you understand my broken english?

and no need black magic like this as an argument...


this will be enough as a solution!

only cost $3 - $10.

and with proper soldering practice and skill, you might not need either one above. and you wont damage the delicate neighbooring parts, if you do it correctly.

[ejeffrey]

I agree that a new socket is the "right" way to fix this.  However, desoldering a big 40 pin DIP is a daunting task for me, as I don't have a proper vacuum desoldering iron

Cut the pins on the old ZIF.  Desolder the pins one-by-one using a tweezers to pull the pins out.  You can clear the remaining solder with a cheap plunger style solder sucker.  There should be very little chance of damage.

I don't think vacuum irons are worth it.  Hand pumps and solder wick are cheap and effective, and if you are going to invest in something fancier a hot air station is more versatile.

[mightyohm]

Cut the pins on the old ZIF.  Desolder the pins one-by-one using a tweezers to pull the pins out.  You can clear the remaining solder with a cheap plunger style solder sucker.  There should be very little chance of damage.

I don't think vacuum irons are worth it.  Hand pumps and solder wick are cheap and effective, and if you are going to invest in something fancier a hot air station is more versatile.

The socket sits flush against the PCB, so cutting the pins would be challenging.

[nukie]

Do you have a Dremel then? You can use it to cut it to multiple 'areas' to help with your desoldering.

Detoxit and the likes is only a temporary fix. Preventive solution is for long term. Are you using a good branded socket, such as 3M? What is the material for contact plating of your socket. How many cycles is it rated? You can find all these on the spec sheet.

[mightyohm]

It's a black Aries socket with tin plating on the contacts.  I have no idea what part number it is, or whether it is genuine - it was cheap and came with a PIC programmer I purchased several years ago.

I never had an issue with it until I left it in the garage for a while (where "a while" is measured in years).  I think the contacts corroded slightly, and now it doesn't work unless I "snap" the lever closed a couple times (probably to break through the oxidation).  I keep hoping it will get better with use, but that doesn't seem to be the case.

The advice about using a dremel is consistent with my first instincts, I'll probably go that route if I can't find a fix.

[SgtRock]

Dear Mightyohm:
--With regard to the recommendations by Mechatrommer, let me say that I completely agree with the part about mechanical repair of the ZIF socket. I hope it turns out this is the problem. However with regard to Mechatrommer's statement that:

"unless there's visible significant amount of rust, maybe the problem is not the "cleaning solution at all".

1) Ferrous materials are almost never used on the surfaces of soldered components, because plain old iron just does not solder very well. Indeed that is why one almost never sees ferrous oxide in soldered connections. In most cases where mechanical insertion is involved, any corrosion or dirt can be difficult or impossible to see
2)I said:

 "My advice was strictly confined to the problem of oxidation. If the problem is mechanical in nature then obviously a new socket would be the thing to try.".

--I do not think I, or anyone else said that oxidation "IS" the problem.
3)The reference to the "real problem" make it sound like someone has been misleading you.
Reflow appliances that heat all the solder connections on the board at once are problematic for obvious reasons. Hot air may work, especially if you block off of the rest of the board with aluminum foil. If the back side of the ZIF socket is blocked by the body of the socket a solder sucker may not work. It would be kind of like trying to use your mouth to get beer out of a standing beer bottle. Likewise turning the board upside down and using a solder sucker (which is awkward and difficult) may not work either due to capillary action. I have done this very thing many times and it "taint easy McGee".

--With regard to the recommendations by nukie. I completely agree with his recommendation to obtain a high quality socket, gold plated if possible. I also agree that a Dremel  tool could be used to chop up the socket, to make desoldering easier, but do not let your hand slip.

--Nukie's statement that:

"Detoxit and the likes is only a temporary fix."

--Is far from being completely correct. Sometimes it turns out that the DeoxIT procedure I outlined will not be a permanent fix, certainly, but only because of other underlying problems not related to the treatment, like corrosion underneath the plating and so forth. As I already stated the treatment will not solve mechanical problems, only problems of dirt and corrosion.  I do not think I could in good conscience recommend blanket replacement and re-soldering  of all components in all cases where intermittent open is the problem. In some cases the problem is merely dirt and or corrosion, plain and simple. DeoxIT products are used successfully  by thousands of professional every day for repair and prophylaxis, and they not at all like nostrums being pushed by snake oil hucksters on the shopping channel.

--And, finally to the problem at hand. If you are sure your only choice is to desolder the socket, I have one recommendation in addition to the ones already stated by others. That is ChipQuick. Mount the board upside down in or on a vise so that you can reach the bottom and the top. Pull down on the socket while keeping the ChipQuick liquid and it should slip out easily. You can get ChipQuick at Digikey for $13.50 (which is enough to do several projects),  at the Web page listed below:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=SMD1-ND

--Also please see below a video of ChipQuick being used to remove an SMD component with 40 odd pins:

Chip Quick Review Easy IC Chip Removal W/ Flux - Video

--Sorry to be so long winded, but I felt it necessary to correct some misapprehensions and erroneous assertions. Best Regards
Clear Ether

[Bored@Work]

However, I have tried this approach before, and ran into an issue - on my PIC programmer, the force of opening the lever on ZIF socket was enough to bump the ZIF out of the IC socket it was sitting in - so I had to hold the ZIF socket in place to keep it from coming off - not so good.

And fix the ZIF socket to the normal socket with hot glue.

[SgtRock]

Dear Mightyohm:
--I am afraid BAW has you there. He did say to use hot glue. By the way, did you notice his "middle finger to the world" comment at the bottom of the post:

"I delete PMs unread. If you have something to say, say it in public. I love the sound of a "you are not helpful" whining in the morning."

He puts this quote in all of his posts. He must have been getting a lot of PMs formerly. No doubt due to his charitable attitude. The statement does not scan very well. To quote Mark Twain "it has a kind of simpering, monkey with a parasol gait to it". It seem to be referring to a "whining", but surely he must mean a "whine". That way his misanthropic utterance would merely be clumsy, instead of clumsy and ungrammatical. Best Regards
Clear Ether

[Zero999]

I don't blame BAW for his signature. On another forum I used to get many annoying PMs from people asking for help. I don't mind helping people but I don't do it via private message because other people can't: benefit from my replies, suggest other things or correct me if I'm wrong. It's not so bad round here but I always tell people to start a thread if the PM me for help.

[SgtRock]

Dear Hero999:
--I take your point. But do you not agree that. "I delete PMs unread" or "Please to not send PMs" would cover the situtation adequately. Why include an ungrammatical and hostile statement with every post.

--I only PM other members, if they request it, and I do not really want people to send me unsolicited and or hostile PMs, but I do not think I am going to call anyone a whiner in advance, just in case.
Best Regards
Clear Ether

[nukie]

Hey guys can we stick to ZIF sockets? opinions tug-war is good but personal bashing is not constructive. Don't judge someone with your feelings unless you want to bed him/her.

[Uncle Vernon]

I'm surprised at the need for hot glue in BAW's solution, like he and Jeff I've experienced similar issues, but found that if the regular socket below the ZIF was a quality machined item, the force needed to dislodge the ZIP was substantial. Yeah I know. two expensive sockets, but I figure if you only get 80 odd years on the planet the least amount of that time you spend redoing repairs the better.

[SgtRock]

Dear Mightyohm:
--You can find a 40 pin gold plated DIP socket at Digikey for $2.81 at the below link:

http://parts.digikey.com/1/parts/297142-40-pin-solder-tail-dip-socket-40-6518-10.html

--And you can find a 40 pin gold plated ZIF socket also at Digikey for $13.92, see below link:

http://parts.digikey.com/1/parts/297076-40-pin-zif-socket-gold-40-6554-11.html

--Digikey's shipping is very reasonable. If these are not perzactly what you need, just let us know, and we will find you something that'l do er. Please let us know how the desoldering goes. Best Regards
Clear Ether

[Milacron]

SgtRock and Milacron - thanks for the suggestions on cleaners.  Both of the ones mentioned are quite expensive (particularly Stabilant), costing more than a new socket.  I guess I need to trade this off against the possibility of destroying the Dragon by trying to remove the ZIF.

 

I hear ya, but you don't buy Stabilant for one project.  One tiny bottle may last a decade or more, as you typically only need a few drops of it per incident.

[Excavatoree]

Mightyohm - Your profile indicates you are in the US, so shipping won't be prohibitive.  I'd be glad to change your socket as I have an antique, through-hole re-working soldering iron/vacuum pump. 

Send me a PM if you are interested - but I understand if you'd rather not send your board to a somewhat complete stranger with unverified skills.   

I used to use the hand vacuum pump to remove 64 pin, DIP package CPUs from VCRs - holding the soldering iron with one hand with the pump in the other, sucking the solder,  pushing the plunger against my leg, and continuing - 64 times. (or more if one try didn't get all the solder out of one or more holes.) 

I was very happy when the boss bought me an ancient de-soldering tool.  It did not have a vacuum pump - it connected to an air compressor and used a venturi to suck the solder.  (In fact, I'd like to have one of those - they seemed to be more reliable.)

(Sorry everyone, at least I was somewhat on-topic (removing through hole components) with this rambly post.)

[mightyohm]

Sorry, I missed the original recommendation to use hot glue.  I've done that in the past, with some success.  Using a machine pin socket sounds like a good idea too, and $3 is acceptable.   

Does Chipquick work well on thru-hole parts?  I've never tried it.

Excavatoree - Thanks for the offer to help!  Let me see what I can do here with my dremel and my solder sucker.  It will be a few days as I am traveling this weekend, but I'll report  back next week with my progress.

[SgtRock]

Dear Mightyohm:
--Yes it works. I just removed a 24 pin DIP socket using it, since I did not want to possibly destroy the socket or the board. It should not be any problem if your iron has enough mass and enough heat to do the job. I use a Hakko 936 with a converted wand to carry larger mass 908 tips. I have the larger chisel tip mounted.  Since you were talking about desoldering I assumed you had more than more than enough iron to do the job. I should have explained further about the heat masses involved.

--You just have to be able to keep the ChipQuick above the melting point of the solder holding the DIP pins. It seems hold heat for a very long time. All it does is greatly increase the total mass of the the material in contact with board, the pins and the meniscus of the solder around each pin. So the surface area of contact between the ChipQuick and the target solder and pins is quite large, relatively speaking. I think any but the wimpiest iron should not have any trouble elevating the temperature of the ChipQuick well above the melting point of even silver solder. The flux you get with the kit seems to work well and the material clumps up rather well, allowing you to push it off of the board rather easily, with out it trying to join up with everything else. You just have to let it start to solidify then push it off the board with your iron. It actually much easier that it sounds. ChipQuick is hypoeutectic, that is it does not a have sharp melting point. ChipQuick also contains Gallium which lowers its plastic melting range, it key feature. When the ChipQuick is just starting to solidify is is well below the melting point of ordinary solder, and will not try to join up when you push it away.

--It is quite possible a solder pump will work without the Dremel. It will almost certainly work if you eliminate the socket from the board side using the Dremel. Just be careful. I know a guy that lost an arm. Best Regards
Clear Ether