When door bell is not working, most
likely there is a bad contact inside the door bell push-button The problem can
be solved by cleaning the corroded metal parts. Hope this article will help
those households having the similar old style door bell system when the problem
occurs.
I
have lived at my current house for more than 23 years. Lately, I didn't hear that much Ding Dong
sound from door bell when visitors came.
Instead what I heard was door knocking.
Last week when I spotted a Post Office car at my mailbox from upstairs
window, few minutes later, I went out to pick up the mails and found a note inside
my mailbox. The note said “a certified
mail cannot be delivered because nobody at home to sign it. It can be picked up
at Post Office later”. What? I was at
home all the time. Since the mail
carrier was only about 50 yards away, I decided to chase the mail rather than
making a trip to Post Office. As I
expected the Postman said he did ring the bell but nobody answered. So I said to myself, that’s it, the door bell
had to be fixed.
I
pulled the door bell button from the wall and there were two wires (red and
white) attached to it by two screws (see Fig. 1). After
removed the screws, I brought the red wire to contact with the white wire and
heard the bell rang. This indicates that
both the chimes and transformer are OK and the problem is from this push-button assembly.
Fig.
1. The old style door bell.
Since
the metal parts of this push-button assembly were pretty corroded (probably due
to oxidation for more than two decades of service), my first attempt of repair
was to sand the contact areas between the wires and the terminals with a file
and sand paper. Unfortunately this did not solve the problem; bell rang only occasionally
even though the button was pushed very hard.
Common sense tells me that when the button is pushed, one metal will
contact with the other metal so an open electric circuit becomes close, which triggers
the door bell action. These two metal
parts inside the push-button assembly should be the source of problem and they have
to be cleaned.
To
disassemble this push-button assembly, I used pliers to twist its head. Luckily I was able to pull the head out from
its base (see Fig. 2). Apparently, there
are two ridges on the head that match the slots on the base. To separate the head from its base, you turn
the head counterclockwise slightly and pull it out. To reassemble it, you just align the ridges
with the slots, push the head down, and turn the head clockwise slightly to
lock it into position.
Fig.
2. The ridges on the head (top) are alighted with the slots on the base (bottom)
of push-button assembly.
With
the head out, I used a file to file the two legs on the base. To access the legs, the button has to be pushed
(see Fig. 3). For the sheet metals on
the head where the legs will contact, I use file and sand paper to remove the
oxidized layer with dark brownish color until the underneath copper with golden
shinning color was revealed (see Fig. 4).
Fig.
3. The legs are up when the button is pushed.
Fig.
4. The contacted areas of the sheet metals on the head were polished.
After
all these works had been done, the problem was solved. Now my door bell can ding done all day long!
