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Thread: $42 soldering for a 27SF512 socket

  1. #1
    Fuel Injected! WallyCJ7's Avatar
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    Angry $42 soldering for a 27SF512 socket

    During my attempt at trying to tune my system I started getting communication errors with the laptop. I was thinking it was too high baud rate so I lowered it to 4800 and it still had errors and then it went into limp mode I'm thinking. The check engine light was flashing like a strobe light and I found the code was 52 if I remember correctly. ECU RIP.

    Now I ordered a new D2 socket from Moates and soldered it in to a good 7747. Well I suck at soldering and or I over heated the board when I did it or I contaminated the solder joints with whatever that coating is on the board. Now I change a check engine light is on and it want tell me any codes. Good thing I ordered 2 D2's and a S4 low profile ZIF socket because now I think I need to try this again. I also picked up another good 7747 ECU.

    Okay so now for my question:

    What does everyone one use to clean the board of that coating prior to soldering in the socket?


    Can I be overheating the board when removing the old solder?

    BTW solder suckers really suck if your slow...

    and Yes I cracked/cut the original socket and then pulled out each pin with a the soldering iron and pliers.



    Thanks in advance

  2. #2
    Super Moderator Six_Shooter's Avatar
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    What type of solder are you using?

    What type of soldering iron (and watt output) are you using?

    I've never needed to actually clean the board for this operation, but I have used acetone to remove the conformal coating at times, when I needed to do so.

    While it is possible to overheat the board, it would take a LOT of heat to do so. I have my soldering station set to just under 400*C, and many times when I'm de-soldering something like this I will turn it up to about 450-ish.

    While I usually use a good solder sucker for this, I have found that sometimes solder wick works better.
    The man who says something is impossible, is usually interrupted by the man doing it.

  3. #3
    Fuel Injected! WallyCJ7's Avatar
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    Its a nice older Weller power base and stand, but its non adjustable so I cant tell what wattage it's running.
    I went by radio shack and picked up some flux core solder and some de-soldering braid. I guess that's wick.
    I also got some acetone to clean the area using a Q-tip.
    Tonight I'll try and see if cleaning up the connections and re-soldering it will work before I go after screwing up the other ECU.

    Quote Originally Posted by Six_Shooter View Post
    What type of solder are you using?

    What type of soldering iron (and watt output) are you using?

    I've never needed to actually clean the board for this operation, but I have used acetone to remove the conformal coating at times, when I needed to do so.

    While it is possible to overheat the board, it would take a LOT of heat to do so. I have my soldering station set to just under 400*C, and many times when I'm de-soldering something like this I will turn it up to about 450-ish.

    While I usually use a good solder sucker for this, I have found that sometimes solder wick works better.

  4. #4
    Super Moderator Six_Shooter's Avatar
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    You should be able to get the already modified ECMs going.

    It may not be feasible, but if you absolutely can't get them working, I could modify them and test them for you. I'm assuming you're in the US though, so shipping would be expensive just to do that. There may be someone else closer that could do the same.
    The man who says something is impossible, is usually interrupted by the man doing it.

  5. #5
    Fuel Injected! sturgillbd's Avatar
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    I can probably repair the ecm also. If you cannot get it to work, send me a PM. I am in VA.

    Brian

  6. #6
    Fuel Injected! WallyCJ7's Avatar
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    Thanks guys I may take you up on your offer. I find that one pin may not be soldering for some reason - probably dirty. I thought I cleaned everything really good. Now I need to find out how to clean it enough to get it soldered without pulling the whole socket.

    Six_Shooter is not in the US?
    Sturgillbd I may take you up on your offer if this doesn't work.

    The more I fight with this thing the more I'm thinking about switching to a 16197427 just for the security of being able to getting one that doesn't need modification. Since I have a junk 7747 I could make a pigtail to my harness allowing me to keep the (once I get working) 7747 as an emergency ECU.

  7. #7
    Super Moderator dave w's Avatar
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    Quote Originally Posted by WallyCJ7 View Post
    The more I fight with this thing the more I'm thinking about switching to a 16197427 just for the security of being able to getting one that doesn't need modification. Since I have a junk 7747 I could make a pigtail to my harness allowing me to keep the (once I get working) 7747 as an emergency ECU.
    I like that plan! http://www.gearhead-efi.com/Fuel-Inj...out-Directions!

    dave w

  8. #8
    Super Moderator Six_Shooter's Avatar
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    You can get solder flux in a pen, paste or brush on format to help with cleaning contacts. I prefer pen or brush on format for re-work/repair/modification.

    No, I'm not in the US.
    The man who says something is impossible, is usually interrupted by the man doing it.

  9. #9
    Fuel Injected! sturgillbd's Avatar
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    Flux will definitely help soldering the socket into the double-sided board. Here is what I use at home for desoldering through-hole chips. It works great but has become quite expensive since I bought mine. http://www.mcmelectronics.com/produc...FYRFaQodYqQAvA It was $139 when I bought it several years ago.
    As for going to a 16197427, that is what I used on my Willys Jeep. I have tuned a 7747 and an 8746 based transplant. It doesn't take as long to get data points at different loads and rpm etc. It just has a lot more tables etc in the bin file. You really need to use a VSS with the 7427 also.

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