question about soldering chip holders

pfroment

New Member
I an using the latest m14 chip for my project. I wrote the code, it is perfect. Wired the project on a breadboard..chip works perfectly. Wire the project on a project board ( I am using chip holders with cyclendrical fingers and one with clip type fingers. Both bought on eBay) plug in the chip and the project works perfectly for a day or so then quits. I install the chip back into the breadboard test bed and the chip performs flawlessly. It will not work in the final project board. I have tested the board completely and all components are fine. This has happened on 5 different project boards that I have made. I narrowed it down to the chip holder. Is there a special way to solder the chip holder to the board? Is there a way to assure contact between the chip and the holder? Can I solder a chip directly to the board to prove to myself that it is the holder. I must be doing something wrong
 

westaust55

Moderator
The "cyclindrial" / machined pin type are usually of better quality but may be a little more difficult that the "clip"/spring type to remove IC's from.

I have never had a problem with either type.

Have you tested with a multimeter on ohms setting to verify that all the pins are soldered well and there are no cold/poor joints?

Maybe posting some clear photos of both sides of a couple of the problem boards and folks might see something.

It is possible to solder an IC directly to a PCB and if your are reasonably proficient at soldering the Ic will not be damaged. However let's try and get to the bottom of why you circuit works on breadboards but not the PCBs.
 

hippy

Technical Support
Staff member
You can solder the chip directly to the PCB but we would not recommend that as common practice. The normal process would be to use a socket, leaf-spring or turned-pin. Both should be reliable and each will have been used in millions of projects without issue. Even with poorer quality sockets failure should not be occurring over such a short time.

It is hard to imagine what issue there may be with soldering other than dry joints so it could be something about the PCB or the circuit design. That it fails on five boards may be significant, something systemic.

Are the boards single-sided or double-sided ? If double-sided and tracks join at the socket pins from both sides without a through-hole plating that may cause some issue.

It might be worth posting photos of one of your boards here so members can take a look to see if there is anything which may look problematic.
 

techElder

Well-known member
Commonly referred to as an "IC SOCKET". Buy some from Mouser Electronics. eBay may not be the best source.
 

premelec

Senior Member
@pfroment - it is unusual to have that many failures due to sockets... intermittent contacts and such happen. If you can't find the problem by soldering in a chip to your board please submit pictures of your defective boards - top side and bottom. Some common troubles are tiny solder bridges between adjacent pins and inadequately wetted solder to the socket pins. i use an inspection lens. Good luck with it.
 

pfroment

New Member
When I get back from vacation, l will first solder a chip directly to the board. This will prove the board design. If that works then I will focus on ty ic socket's soldering. I will reheat each tab to assure a good solder joint. Re insert a proven chip and see what happens. I will let you know. Is there a way to assure good contact with chip pins and socket? Could it be with the project board type. I am using the type with the copper rings one on side only, again the cheapest I can get on eBay
 

srnet

Senior Member
I would not recommned soldering a chip direct to a board, if the board is faulty then unless your are a skilled de-solderer, you have lost a PICAXE.

If in doubt use a turned pin type IC socket, not as expensive as a new PICAXE.

I just do not recall a failure of the turned pin sockets in normal use, but then I am but a beginner with only around 40+ years of experience.

It would be informative if you explained exactly how "I narrowed it down to the chip holder"
 
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hippy

Technical Support
Staff member
Is there a way to assure good contact with chip pins and socket?
Not really. The quality of contact is inherent in the design and manufacture of the sockets. Leaf springs can get flattened but will still usually provide good contact. Trying to adjust leaf springs usually results in damaging the contact and creating worse problems.

Straightening the chip legs with a leg straightener is about the only advice I have to best ensure good contact.

Could it be with the project board type. I am using the type with the copper rings one on side only, again the cheapest I can get on eBay
It is possible. I do not personally like those kinds of boards. I find them hard to solder to and too much heat or re-soldering can cause the rings to come away from the board. They are better suited to wire-wrapping than soldering in my opinion.

Sometimes buying cheap can be a false economy. If you post a photo of the board's wiring we can better assess the issue you may be having.

It is probably better to do that before soldering your PICAXE direct to the board as, once soldered in place, it may be difficult to remove and reuse again.

Did you check the Serial In connection as suggested by Technical in post #5 ?
 

erco

Senior Member
I've seen lots of bad soldering and wiring mistakes. Never seen a bad socket, even from China.

 

pfroment

New Member
I got from vacation and thought i would give it another shot. Got some new m14-2 chips and programed one. Tested it on the test bed and works perfect. placed it on the project board and nadda... here is what i did. removed the chip, retested it, placed it on a blank breadboard.
insured wires into the ic socket and wired them to the chip on the board spot for spot. c.1 to c.1 and so on. the project board worked perfectly
installed the chip back in the project board and guess what. NADDA. The chip is good, the ic socket is good and the project is good. Why won't they play together? gonna build one more and see what happens
 

premelec

Senior Member
See post #5 again... please post pictures of your unit that does not work... probably a simple error - the kind we all make... ;-0
 

inglewoodpete

Senior Member
the project board worked perfectly
installed the chip back in the project board and guess what. NADDA. The chip is good, the ic socket is good and the project is good. Why won't they play together?
Hmm. One of the blue statements above is incorrect :).

I would never purchase IC sockets from a doubtful source. There may be a reason why the supplier was able to purchase a large number of cheap IC sockets Eg. water damage. The few cents you may save can take hours to diagnose and rectify, as you're discovering. Of course, the IC socket may not be at fault, either.

Thoroughly check the orientation of all the polarised components: diodes, electrolytic capacitors, transistors and ICs.

Before you start butchering your circuit board, I suggest you go over the board with a ohmmeter (NOT the continuity 'beeper' that many multimeters have). Does every component-to-component connection show a (very) low resistance?

Once something has worked and then stops working, the most common cause in electronics is the connections. Inexperienced operators need to consider solder joints too.
 

OLDmarty

Senior Member
Is the actual "project board" a board you board from somewhere? maybe it has bad track layout/shorts or something? OR are you just using Vero/stripboard or something?
 

hippy

Technical Support
Staff member
Why won't they play together?
Very hard to guess but you could help us make an assessment if you could post a photo of your board.

If it works with the chip jumpered to where the socket is, but doesn't work when the chip is in the socket, that does suggest it is a fault with the socket.
 

OLDmarty

Senior Member
If it works with the chip jumpered to where the socket is, but doesn't work when the chip is in the socket, that does suggest it is a fault with the socket.
I've experienced quite a few IC socket and pin-headers that have the occasional pin that isn't tinned properly and won't solder at all.
It's possible to have a pool of solder form around the pin without actually connecting, or partially connecting thru the corroded pin.

Closeup photos are probably the only way we can start to examine & confirm things to try.

I'd pull the socket out and try another one.

Additionally, are the copper tracks for the IC pins actually soldering too?
 

westaust55

Moderator
So it's back to post 2.

If not already done test continuity of the circuit to spring side of sockets with an Ohm meter to check actual ohms resistance.
If done then let us know you did the test and the results. Measure ohms - as mentioned above don't just check with a buzzer.

Post some clear photos of both sides of a couple of the problematic boards.

No one can provide any definite answer without additional information.
Otherwise folks are best guessing.
 

erco

Senior Member
Gotta be your board. You may have a bad solder joint on your PCB. Many boards have a protective lacquer coating over the copper pads that must be sanded off before soldering. And don't blow off premelec's bypass cap suggestion. We're all just guessing here. Per hippy, you need to post clear photos of the front & back of your board ASAP. It will probably be a matter of minutes before someone spots your problem.
 

RexLan

Senior Member
It "appears" that OP is not concerned enough to help himself so why pursue it further?

8 times he has been asked to post photo ... dismissed.

Technical asked a question ... dismissed.
 

newplumber

Senior Member
erco -->"Gotta be your board. You may have a bad solder joint on your PCB"
I agree
and its nice to read the pros all fixes , I bought some cheap china pcb boards and the copper connections were so bad placed that some of them were touching others
of course i didn't find it out till I had it all soldered and since I am not a pro I was spinning circles thinking it was my design so maybe its a junk board from the start
my two cents anyway
 

pfroment

New Member
I hard wired a chip to a new board and it works perfectly. I used what little of 60/40 rosin cord that i had on this. i need only about 7 more of these so i guess i will hard wire them all. if it works don't break it. thanks for the input, been a lot of help
 
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