Bought my kit, need help.

SgtWookie

Joined Jul 17, 2007
22,221
A question- Ive been playing with the kit for a while now, and I have discovered that when I tap the board right by the 555 timer, it moves to the next LED in the sequence. When you fry a chip, what happens to the circut with the chip?
It can suffer in a number of different ways.

Holding heat on a pin for too long is one easy way to kill an IC. If it doesn't take solder after ~3 seconds, then your iron is dirty, tip is loose, iron not hot enough, or your parts/pads are not clean. Holding the iron on a part and pouring on the solder just won't help things at all.

If you are certain the soldering on the 555 is good, then you may have overheated it enough for a substrate bonding wire to pop. Replace the 555 with a new one and see if that takes care of it.
 

Wendy

Joined Mar 24, 2008
22,360
While not for everything, I like to use IC sockets when I can. I got into the habit from my early days of kit building, for basically the same reasons you are fighting.
 

Audioguru

Joined Dec 20, 2007
11,249
I used IC sockets for nearly all the projects I built and sold during my electronics career.
But I never had to replace an IC!

I had tens of thousands of an equalizer project built, tested and sold without IC sockets.
Two had a problem. One had the IC installed backwards and the other had a defective supply bypass electolytic capacitor. Tens of thousands of TL074 quad opamps on them were fine and I am glad that I didn't use sockets (therefore the last few production runs used surface-mount ICs which also produced no problems).
 

Thread Starter

Joeyvenkman

Joined Nov 19, 2011
15
Sorry I havent posted in forever guys. But for christmas, I did actually acquire a Radioshack DMM, along with other electronic goodies. I am certain that my soldering on the 555 and 4017 is good. Now, where should I test on the 555? Thanks!
 

Audioguru

Joined Dec 20, 2007
11,249
At my last job I needed a good DMM but the one used by the company was defective. So I bought a Fluke fairly expensive one. I still have it many years later and it still works perfectly.
My boss said my Fluke was too expensive so he bought a fairly expensive DMM from RadioShack that costed less than mine. It failed in one week, RadioShack couldn't repair it and had no replacement.
 
Top