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View Full Version : Is BS2P40 supposed to snap into the PDB?



latigerlilly
02-10-2007, 01:04 AM
I keep having a problem where something should work, but it doesn't. So, I pull out my BS2P40 and clean the connection and re-insert and voila, it works. However, maybe the connections are not dirty but loose because another poster here said it was very difficult to pull out the chip, but mine practically fell out. So, my question is this, is the chip supposed to snap in? I am afraid to push hard enough to hear a snapping sound because the owner's manual did not mention it and I'm afraid that the snap may be the sound of it breaking not connecting tightly. So, just push firmly, but no "snap"?

Chris Savage
02-10-2007, 01:12 AM
The PDB has machined pin sockets. These typically exert a tighter grip on the pins and thus require slightly more pressure to insert the module. The pins should be inserted down into the socket holes, not just the cupped area. The module should be very close to the black resin holding the sockets together. Can you take a close-up picture of your setup if in doubt?

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Chris Savage
Parallax Tech Support

Steve Joblin
02-10-2007, 01:16 AM
The chip should be held in place by friction... the only "snap" you should hear is perhaps the when the botom of the chip gently touches the top of the chip socket... reasonable evenly applied pressure should be exerted until the chip is sitting flat against the socket.

Mike Green
02-10-2007, 01:19 AM
There's no "snap". There's a certain amount of friction between the pins and the sockets and the more pins you have, the higher the friction. Generally, 40-pin parts are much more difficult to remove and re-insert than 24-pin parts just because of that. If the chip is so loose that it "practically falls out", it probably isn't making a good connection. If the socket is good, it should be rare that you have to remove, clean, and reinsert the chip. Part of the purpose of the pressure between the pins and the socket is to get an air-tight seal since oxidation is the usual cause of poor contacts. That's not much of an issue with gold to gold contacts, but most IC pins are tin plated since they're expected usually to be soldered. Either tin or gold plated sockets are normally used (tin because tin oxide is conductive) with the socket geometry designed to exert enough pressure on the side of the pins to exclude the air at least in a small area.

PhilippineEagle
03-12-2007, 10:24 PM
I broke one of the pins in my BS2. How can I replace that particular pin?

Newzed
03-12-2007, 10:31 PM
There are two ways. Solder on a new Stamp pin, or, plug a short length of bare 22 ga. wire into the Stamp Socket. Plug in the Stamp. Very carefully form the bare wire to contact the broken pin, cut off the excess and solder it in place. I have Stamp pins - I will send you one if you give me your address. My e-mail is Newzed@aol.com (mailto:Newzed@aol.com).

Sid

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Yesterday is history, tomorrow is a mystery, and today is a gift.

That is why they call it the present.

Don't have VGA?
Newzed@aol.com (mailto:Module?Newzed@aol.com)

RobotWorkshop
03-12-2007, 11:24 PM
Another way that works well for repairing a broken pin on any of the Stamp modules is to buy a machine pin socket of the same size and plug the stamp into that. You can just solder a small jumper or solder bridge the broken lead directly to the sockets pin below.

Now, you can just plug the whole thing into what ever socketed board you want. It's a bit taller than the normal stamp module but it is pretty sturdy.....

Best Regards,

Robert

PhilippineEagle
03-25-2007, 10:40 AM
I'm from the Philippines, Sid, so it might be too much trouble if you send just one pin to me. Is there a supplier on the internet where I can buy these pins--like Digikey or RS?

By the way, what's VGA?