PDA

View Full Version : bill r, how do you tell if a relay solder joint is cracked?



ryan roopnarine
12-28-2004, 04:08 PM
do you usually have to use magnification of some type? have the GM and RM out of the car, and the tops of the PCB look like they were manufactured yesterday. i'm seeing what i THINK are tiny cracks on the larger components , but it could just be my imagination. thanks.

ps....do you put new solder onto something like this, or do you just reflow the old stuff?

MBXB
12-28-2004, 04:23 PM
Ryan
I use one of those circular flourescent lights with a magnifier in the middle from Office Depot.
I'd resolder: melt off the old solder and vacuum it off with a Radio Shack Solder Sucker (a spring loaded mini turkey baster with a trigger); then clean off, and resolder with new rosin core.

Bill R.
12-29-2004, 12:19 AM
lenses on a headband that you can buy at any electronics supply house, the good ones have glass lenses and you can get different levels of magnification, they slip right into place ... and then i move the circuit board all around under a good light seeing it from different angles.. sometimes the cracks are very hard to see, if in doubt resolder anyway. Heres a pic shot at the macro setting on my camerahttp://www.bimmernut.com/%7Ebillr/images/fuelpumprelay1%20copy.jpg





do you usually have to use magnification of some type? have the GM and RM out of the car, and the tops of the PCB look like they were manufactured yesterday. i'm seeing what i THINK are tiny cracks on the larger components , but it could just be my imagination. thanks.

ps....do you put new solder onto something like this, or do you just reflow the old stuff?

winfred
12-29-2004, 12:33 AM
ahh one of my favorites, a volvo main/fuel pump relay


lenses on a headband that you can buy at any electronics supply house, the good ones have glass lenses and you can get different levels of magnification, they slip right into place ... and then i move the circuit board all around under a good light seeing it from different angles.. sometimes the cracks are very hard to see, if in doubt resolder anyway. Heres a pic shot at the macro setting on my camera