So, you can laugh at me...

[ghillie]

I got the FM25B kit for my birthday. Its sat on my desk for a few months now. I started building it one day, and when I started, I think I messed something up. Steps 1-6 were already installed on the circuit board, so now I'm on step 7. You can laugh, but I'm not sure how to position the U2 and its socket. I think I already installed it the wrong way... how do I take it out? And what is the correct way to put it in? Thanks in advance...

[Joe Chezk]

Im not sure what U2 is as I dont have one of those kits in front of me, but as a general rule, an IC has a dot impressed on the IC, towards one end of the chip, on one side, the socket should have the same mark on it, put the IC in so the dots are on the same side, and towards the same end. Sombody else who has this kit can give you more detailed instructions, so best wait for another response to make sure.
Grandpa Joe

[Ramsey Tech Z99]

The socket can go in the circuit board in either direction. Turn to page 9 and find U2, notice that the notch on the IC is next to R12. When installed your IC should look the same as the one in this diagram.

If you installed the IC before the socket and it is in the correct direction, leave it in the board and forget about the socket. If you installed the IC before the socket and it is in the wrong direction it will have to be removed.

A few different methods exist for removing IC’s. The method I prefer is to start in the middle of one side of the IC. Use enough solder to Flood all of the pins on one side of the chip. While still heating the puddle of solder use a small screwdriver to pry up the heated side of the chip until the leads come out of the board. Then repeat this procedure on the other side of the IC. Finally clean off the excess solder with a solder sucker or solder wick. The circuit board solder pads for the IC have feed-through’s or via’s that connect the bottom-side pads to the top-side pads. If these are damaged open circuit runs can occur. This procedure protects those feed-troughs or via’s.

Another method would use a soldering iron and solder wick or a solder sucker to heat and remove the solder. The problem with this method is that removing all the solder is extremely difficult. When the IC is removed from the board it can pull out the via’s.

[ September 28, 2004, 01:36 PM: Message edited by: Ramsey Tech Z99 ]