Magnavox TB100MW9 Digital TV Converter, Intermittent
After about 6 years of service, my Magnavox TB100MW9 Digital TV Converter
developed ann intermittent problem, where it would take several minutes to
come on and then the picture would come and go. I took the cover off and
found that by gently moving a vertically-mounted IC, I could reproduce the
problem. From other units of the same model that I have, this design was
only used for serial numbers 4000000 and up. The IC is mounted to a substrate
board that is then soldered into the main board. Inspection of the pins on
the main board that solder to the substrate showed that there were poor
solder joints with visible cracks, probably dating to the original
manufacture, and which took 6 years to oxidize and lose connection.
Resoldering these joints, using a miniature iron along with visual guidance
from a binocular microscope with variable zoom, solved the problem.
on Apr 27, 2015 | Magnavox TB100MW9