PIC 16F737 broken pin help

[tempus]

Hey all;

I managed to break pin 15 on my PIC 737 uC. I don't actually use this pin in my circuit (it's RC4 btw), but the PIC won't work in my circuit, nor does my programmer detect it. Is there any way to salvage the device or do I need to get a new one? I thought of trying to ground the pin, but there isn't much left to solder to and if there is a chance to salvage it, I don't want to ruin it further. Should I give that a try?

Thanks

 

[JimB]

Is pin 15 just used for RC4, or does it have a secondary use during programming?

Why do you think that grounding the pin will do any good?

In the past, I have in extreme situations, carefully scraped the plastic body of a chip away from a broken pin in an attempt to recover a bad situation.
And it worked!
Try it if you wish.

Generally speaking, ICs with broken legs are a bit like dead parrots...

...not repairable, you need a new one.

JimB

 

[tunedwolf]

Like JimB, in a pinch, I have milled away the plastic carrier around the broken pin and soldered a wire on.
I would fit the device in a turned pin socket and solder the wire to the socket just to get me by until I could get a replacement, but as has already been pointed out, it's the kind of thing you do at 3am when you are bread boarding something that can't wait
Get a replacement and fit it in a turned pin socket to begin with, in order to protect the pins when plugging and unplugging into your breadboard.

 

[tempus]

Thanks for the replies all. Jim - I wondered if the grounding the broken pin might help just because it's good practice to keep all unused pins at a definite logic state, and that since the pin was broken, it might somehow be causing problems because it is now floating. Shortly after I posted the original post, I tried to program the PIC a few more times and got it to work. I'm not sure why, but it took a few tries to detect the PIC, and when it did it programmed it and things are working fine now.

Thanks again

 

[skimask87]

Keep it from floating? Set it to an output.

 

[atferrari]

I recall suffering that during a weekend. Since the widest part of the leg was still accesible, I just soldered a short wire and the micro worked OK.

Curious, how it happened?

 

[Mosaic]

That usually happens when u push a chip into a socket and a pin misses its mark. Then u try to straighten it with a bird beak which breaks it. Best to straighten with a tweezer that bends more gently.

 

[atferrari]

Like JimB, in a pinch, I have milled away the plastic carrier around the broken pin and soldered a wire on.
I would fit the device in a turned pin socket and solder the wire to the socket just to get me by until I could get a replacement, but as has already been pointed out, it's the kind of thing you do at 3am when you are bread boarding something that can't wait
Get a replacement and fit it in a turned pin socket to begin with, in order to protect the pins when plugging and unplugging into your breadboard.

Otherwise, play safe and buy 4 of the same in advance; what I started to do years ago and never had a bad moment again

 

[dr pepper]

Theres a bit of lead length to the substrate, in emergencies I've ground back some of the plastic package with a dremel and soldered on a leadout wire, you can do it with a small tip solder iron.

Bird beak, is that a language thing for long nosed pliers?

 

[JimB]

Otherwise, play safe and buy 4 of the same in advance; what I started to do years ago and never had a bad moment again

Very wise, I do the same.*
Allows for the "Oooh, I never thought of that!" situation when the magic smoke is released.
Or more likely just sit there and does nothing, does not even get slightly warm.


* Unless the device is VERY expensive.

JimB