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Soldered a MC backwards, unsoldering is almost impossible
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Soldered a MC backwards, unsoldering is almost impossible

by lechuga on Mon Jul 07, 2014 1:03 pm

Hello,

I completed building the main board, except I noticed that I put one MC in backwards. I bought de-soldering materials and I can't get the MC out.

Is it possible to fry the inside of the MC if my soldering tip makes contact for too long with one of the prongs? In addition to trying to de-solder, I'm concerned that I may be damaging the MC as I try to melt and absorb the solder connections with my solder wick. Any suggestions? I'd hate to have the entire build ruined by a single MC screw-up.

lechuga
 
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Re: Soldered a MC backwards, unsoldering is almost impossibl

by adafruit_support_rick on Mon Jul 07, 2014 4:11 pm

I use a solder sucker. That doesn't require a lot of heating, the way solder wick does.

This one is very nice, but expensive:
https://www.adafruit.com/product/1597

Cheaper, works well:
https://www.adafruit.com/product/148

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Re: Soldered a MC backwards, unsoldering is almost impossibl

by lechuga on Mon Jul 07, 2014 4:21 pm

Thanks for the reply. I have both a solder sucker (similar to your second link) and a wick. I have tried both, only clearing about 3 prongs. The solder around the other prongs will melt, but will not budge. I have tried for a long time now, but I'm afraid I might be doing damage by exposing the prongs to too much heat (frying the inside).

If it helps, I can put the batteries in and report with which lights light up. Not every "section" lit up when I turned the unit on to see what worked. Will this help any?

lechuga
 
Posts: 8
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Re: Soldered a MC backwards, unsoldering is almost impossibl

by adafruit_support_rick on Mon Jul 07, 2014 4:38 pm

You can always just clip out the bad chip and replace it. It should be a lot easier to get the individual pins out.
There's only on microcontroller on the board, and that one should be socketed. The rest of the large chips are simple shift registers.

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Re: Soldered a MC backwards, unsoldering is almost impossibl

by lechuga on Mon Jul 07, 2014 4:47 pm

Sorry, I have the terminology wrong. I thought they were MCs for controlling each array section of LEDs. It's one of the 8 SRs that I put in backwards.

Is my only option to purchase a replacement or is there amnesty for first-time mistakes? Thank you.

lechuga
 
Posts: 8
Joined: Thu Sep 05, 2013 4:20 pm

Re: Soldered a MC backwards, unsoldering is almost impossibl

by adafruit_support_rick on Mon Jul 07, 2014 5:53 pm

We don't actually stock the shift registers individually. You can get them at Jameco:
https://www.jameco.com/webapp/wcs/store ... llDownView

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