On 16/02/2021 8:08 am, JB Haskins wrote:
I have a small, handheld geiger counter made by a firm called RDX
Nuclear (model is DX-1).Â* Unfortunately, a much younger family member
than I decided to try putting a 9V battery in it, but he put it in the
wrong way before I could intercept him.Â* Now, when the activation button
is pressed, all I'm getting is a constant tone.Â* Within the tone, I can
hear individual clicking as if it is still taking counts, but that's it.
Â*Also, the indication needle is pegged.Â* Here is an image of the top of
the circuit board:

Â*https://i.imgur.com/kSHzB0T.jpg

Unfortunately, I've never seen a schematic of this unit on the web even
though it seems to be sold all over the place.Â* Contacting RDX, all they
want to do is replace that tiny board... for $120.Â* So, if you hooked it
up backwards, what would you check first?Â* I did check the diodes and
they all seem fine.

**As Phil has stated, the 40106 is likely to be toast. For less than 10
Bucks and 20 minutes work, you could replace every semiconductor in the
thing.

--
Trevor Wilson
www.rageaudio.com.au

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus