"NT" wrote in message
...
On Sep 20, 11:22 am, "Tim Walters"
wrote:
"NT" wrote in message

...
On Sep 19, 2:11 pm, "Tim Walters" wrote:



"NT" wrote in message

...
On Sep 15, 7:59 pm, "Tim Walters" wrote:

Hello. My parents have got an ancient Smiths timer which controls some
outside lights. At the moment, no matter how the timer is programmed,
the
lights are on all the time, unless the timer is actually switched off.
Dad
used to fiddle with it and, miraculously, it did what he wanted. Now,
for
some reason, it won´t.

The timer has an override button on the left. Then there's a row on
three
buttons (hours, minutes, and set). Then there´s a vertical slider with
S
at
the top and N at the bottom. There's a window above the buttons where
the
time appears.

Thanks for any suggestions.

crikey, dont give us anything to work on. Get a multimeter, open the
timer and see whats going on.

Ok. There are three screw-type contacts (like the ones inside a standard
3-pin plug). One is labelled COM, the other teo are labelled L1 and L2.
(There´s actually a mirror-image arrangement on the other side of the
timer
but these are all dead.) There are only two wires - black and red. The
red
goes into the COM and the black into L1. After taking the back off, I
could
see three small cylinders connected to the contacts. A black burn mark
showed that something had burnt out. I took the thing down to a local
electrical supplies wholesale shop and showed it to a very competent guy
there. Getting a new timer wasn't an option because the ones that work
with
just 2 wires are limited to four hours. Getting a new programmable timer
would mean re-wiring the system.

The guy suggested I try putting the black wire into L2, and maybe I
would
have to reverse program the thing (on = off and vice versa). I tried
this
but it didn't work. The lights stay on when the timer itself is switched
on.
The difficulty is I'm not completely sure how to program the thing in
the
first place. For instance, what do N and S mean on the slider? What
exactly
is the purpose of the Override button?

Can anyone suggest anything?

that the use of L2 hasnt worked indicates something more serious than
a fried switch contact (the most common cause). However, I'll say this
once again: we cant possibly fault find it without knowing the details
of how it works, blind, remotely, and without being able to test it.
Either fault find it yourself, or as you cant, at the very least post
a bunch of pics so we've a clue what type of timer it is.

Here are 3 pictures. I hope they're good enough.

http://www.eurotrad-traductores.net/...t/P1010115.JPG

Thanks

Great. So
1. its a digital timer
2. the power ratings indicate its almost certainly triac switching,
not relay
3. the black patch on the pcb should have a fried component on the
other side - it would be usful to get a pic of the whole of that
board, component side.
4. Since this is a triac switcher, the using the L2 trick wont work.



Here are three shots of the underside.

http://www.eurotrad-traductores.net/...t/P1010118.JPG