One of my low-end Home Depot Heath-Zenith Motion Security Lights just
went bad after about 5 years. The light sensor stopped working though
the motion sensor and lights themselves work fine (see below for my
troubleshooting). In any case, the light sensor circuit failure seems
to be a common problem on the low end Heath-Zenith models based on
customer reviews.

Some have recommended the higher priced Heath Journeyman (about $70
vs. $30) which has a lifetime warranty and presumably better quality
construction though others have also had light sensor problems with
them.

So, any recommendations for a durable/long-lasting/good quality
combined photoelectric and motion sensing light?

I plan to use 2 120W-equivalent CFLs so I need a regular light socket
rather than a halogen version. Also, one that uses a relay rather than
a Triac would probably be better.


NOTE: I diagnosed the problem with the light sensor circuit as
follows. First, I confirmed that the motion circuitry worked since the
red motion light flashed properly in the presence of motion though the
light failed to come on even when the photocell was covered with black
tape. Also, in test mode (which bypasses the photocell and the timer),
the motion sensor worked just fine and the lights turned on -- ruling
out a problem with the motion sensor or the lights themselves. Outside
of test mode, the light would never come on. The net implication is
that something was wrong with the light sensing circuitry.

I then took the unit apart and didn't notice anything grossly wrong
with the circuit board (no burnt components or cracked board), though
a couple of solder joints looked suspicious but they ended up being ok.

The resistance across the photocell, however, was low (about 400 ohms),
independent of the light level. However, the photocell itself was ok
since it worked fine when I desoldered it from the circuit (about 50K
in darkness, 1000 ohms in light). So, it seems like there is some shunt
in the circuit. I couldn't find any gross shorts in the board. I also
removed a capacitor in parallel with the photocell, but it proved ok
too. It seems like the problem must be with the IC that is soldered to
the board since that is the only remaining source of short.

At this point, I gave up and decided to look for a new and better unit...