Casio Digital Horn DH100

Dorian's DH100 Page

(also works for
DH200)

(see end of page for
DH500)

These digital horns are little more than
toys but what fantastic fun they are!!

Trouble is they all seem to have
gone wrong.

When switched on all they do is
squeak. If yours is like this then read on.

They can be
fixed! (only
the squeak problem)

I have two, and when the first broke I just thought
that's that, but when the second developed the same fault I started looking on
the Internet for a solution. Then I found that hundreds of people have exactly
the same problem.

That's when I realized it must be a bad batch of
components. Hopefully not a chip because they would be impossible to get now.
What a relief to find that it was just a faulty capacitor. I took my second horn
to bits and did the same repair and that worked too. I live in England and the
cost of the capacitor is approx. 30 pence (50 cents US). Get them from your
local Tandy or electrical repair shop. If you are not confident enough to try a
repair, print this page and take it to your local repair shop.

Shame that Casio didn't tell us what to do on their
website! Anyway, I'm doing it now.

Follow these instructions:-

Remove the mouthpiece, batteries and all the case
screws (don't forget the one in the battery compartment).

Once opened you will see two printed circuit boards
in a stack, remove the screws from the top board and carefully turn the board
over. At one edge of the board you will see the offending capacitor. (C39 which
is 33uF)

Very carefully and without damaging the circuit
board, either unsolder or cut the capacitor out. I used a very small and sharp
pair of cutters to do this. It is also possible to wriggle the capacitor with a
small pair of pliers until it breaks free. Then unsolder or cut off any
remaining legs. Double check with a magnifying glass if possible to be really
sure that you have not left a short circuit here! The capacitor can also leak a
corrosive fluid, make sure the circuit board is dry before continuing. A cloth
soaked with alcohol will clean it.

Make sure you use the right
holes!

Insert a 33uF (or as I did a 47uF tantalum bead )
capacitor in the feed through holes on the board. (see photo)

Any type of capacitor will do as long as its small
enough to fit in the the space available. The working voltage should be at least
6V.

Double check the polarity before soldering in place.
Trim the excess wire off the legs of the capacitor and that's it!!

Re-assemble your horn and enjoy.

Over 1000 horns have been fixed using
these instructions and I thank everyone who wrote to tell me of their success,
but sadly I can no longer have my e-mail address on the page because of huge
quantities of spam.

Fingering Chart

Manual Info

Links to other
sites:-

Paul Fox has a site with details (and
photos) of other fixes and setups. Well worth a visit! http://homepage.ntlworld.com/paul.fox4/casiofixes.htm

DH500
Information.

Several people have told me of their success in
fixing DH500s. The basic fault is the same, bad capacitors, but there is more
than one in the 500.

The large value capacitors are C11, C37 & C42. I
hope this is enough information for you to fix your horn.