Bob Simon wrote:
My wife's reading lamp failed. I replaced the 100W 120V halogen bulb,
which did no good so I pulled out the dimmer circuit. I know nothing
about these but after googling for light dimmer I found this:
http://www.epanorama.net/documents/l...mmer.html#120v

The "typical 120V AC dimmer circuit" uses almost the same components
that are on my dimmer:
two diodes
cap
resistor
pot
diac
triac

The diodes test good one way so I wonder if either the BT137F triac or
the DB3 diac are the problem. Can these be tested with a VOM?


Usually triacs fail shorted, you'll want to rule out the easy stuff
first. Switch, variable resistor, etc. If the lamp doesn't light at all
my first suspect aside those already mentioned is the diac.